Anti-CD115 antibodies

ABSTRACT

The present invention provides anti-CD115 monoclonal antibodies and related compositions, which may be used in any of a variety of therapeutic and diagnostic methods for the treatment of cancer, autoimmune, and other diseases.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application under 35 U.S.C. § 121 of U.S. patent application Ser. No. 15/760,322, filed Mar. 15, 2018; which is a U.S. National Phase Application filed under 35 U.S.C. § 371 from International Patent Application No. PCT/US2016/052063, filed Sep. 16, 2016, which claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 62/220,147, filed Sep. 17, 2015 and U.S. Provisional Application No. 62/219,578, filed Sep. 16, 2015, each of which is incorporated by reference herein in its entirety.

SEQUENCE LISTING

The Sequence Listing associated with this application is provided in text format in lieu of a paper copy and is hereby incorporated by reference into the specification. The name of the text file containing the Sequence Listing is 000118-0006-302.txt. The text file is 537,274 bytes, was created on Jun. 16, 2020, and is being submitted electronically via EFS-Web.

BACKGROUND Technical Field

The present invention relates generally to anti-CD115 antibodies, compositions and methods of using same. Such antibodies are useful, for example, for treating a variety of diseases, such as oncological and immunological diseases.

Description of the Related Art

CD115, also known as Colony-Stimulating Factor 1 Receptor (CSF1R) and macrophage-colony stimulating factor receptor (M-CSFR), is a cell surface receptor tyrosine kinase belonging to the platelet-derived growth factor family. CD115 has two structurally unrelated ligands, namely CSF-1 (M-CSF) and IL-34. CD115 is expressed by hematopoietic stem cells, myeloid cells, including monocytes, macrophages, osteoclasts, dendritic cells, and microglia, neural progenitor cells, and epithelial cells, including Paneth cells (Stanley and Chitu, Cold Spring Harb Perspect Biol 2014; 6:a021857).

Dysregulation of CD115, and/or its ligands, is associated with proliferative diseases and disorders (e.g., neoplasms, tumors and metastases), as well as immunological and neurological diseases and disorders. The present invention provides chimeric and fully human anti-CD115 antibodies, including CD115 antagonists.

SUMMARY OF THE INVENTION

The present invention relates to anti-CD115 antibodies. More specifically, it relates to chimeric anti-CD115 antibodies generated from an AlivaMab® Mouse, fully human anti-CD115 antibodies produced therefrom, and methods of use thereof.

One aspect of the invention provides an isolated anti-CD115 antibody, or an antigen-binding fragment thereof, comprising i) a heavy chain variable region comprising a VHCDR1 selected from any of SEQ ID NOs:436-543, a VHCDR2 selected from any of SEQ ID NOs:868-975, and a VHCDR3 selected from any of SEQ ID NOs:1300-1407 and ii) a light chain variable region comprising a VLCDR1 selected from any of SEQ ID NOs:652-759, a VLCDR2 selected from any of SEQ ID NOs:1084-1191, and a VLCDR3 selected from any of SEQ ID NOs:1516-1623.

In one embodiment, the VHCDR1, VHCDR2, and VHCDR3 of the anti-CD115 antibody, or antigen-binding fragment thereof, comprise SEQ ID NOs:450, 882, and 1314, respectively. In one embodiment, the VLCDR1, VLCDR2, and VLCDR3 comprise SEQ ID NOs:666, 1098, and 1530, respectively. In another embodiment, the VH is selected from any one of SEQ ID NOs:109-216. In yet another embodiment, the VL is selected from any one of SEQ ID NOs:325-432. In one embodiment, the VH comprises SEQ ID NO:123. In another embodiment, the VL comprises SEQ ID NO:339. In another embodiment, the VH comprises SEQ ID NO:123, and the VL comprises SEQ ID NO:339.

In one embodiment, the anti-CD115 antibody, or antigen-binding fragment thereof, is human. In one embodiment, the antibody is chimeric. In certain embodiments, the antibody is selected from a single-variable domain antibody, single chain antibody, a scFv, a bispecific antibody, a multi-specific antibody, a Fab, a F(ab′)2, and a whole antibody.

One aspect of the invention provides a recombinant polynucleotide encoding the anti-CD115 antibody, or antigen-binding fragment thereof, described above. Another aspect of the invention provides an expression vector comprising the recombinant polynucleotide. In another aspect of the invention provides an isolated host cell that comprises the expression vector. One aspect of the invention provides a composition comprising an anti-CD115 antibody, or antigen-binding fragment thereof, described herein and a physiologically acceptable carrier.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows ELISA can detect an increase in p-MCSFR. For each grouping of bars, the lysate ratio is neat, 1:2, 1:4, 1:8, 1:16 and 1:32 from left to right.

FIG. 2 shows Bin1 α-CD115 mAbs may block M-CSF and IL34 induced CD115 phosphorylation and Bin 3 35A may block all phosphorylation.

FIG. 3 shows CD115 phosphorylation (p-CD115 or p-MCSFR) measured by ELISA.

FIGS. 4A and 4B show inhibition of m-CSF- and IL-34-induced phosphorylation of CD115 (MCSFR).

FIG. 5 shows binding of anti-CD115 IgGκ mAbs to CD115 expressed on OCI-AML5 cells.

FIG. 6 shows an assay for detecting inhibition of m-CSF (CSF-1) induced phosphorylation on CD115 expressing AML5 cells by anti-CD115 IgGκ mAb.

FIG. 7 shows binding of anti-CD115 IgGλ mAbs to OCI-AML5 cells.

FIG. 8 shows anti-CD115 IgGλ mAb inhibition of CSF-1 induced phosphorylation of CD115.

FIG. 9 shows the IC50 of selected anti-CD115 mAbs. For each grouping of bars, no M-CSF, 10, 2, 0.4, 0.08, 0.016, 0.0032, and 0.00064 ng/ml are shown from left to right.

FIG. 10 shows neutralization of CSF-1 binding to CD115 by anti-CD115 mAbs.

FIG. 11 shows neutralization of CSF-1 induced phosphorylation of CD115 by anti-CD115 mAbs.

FIG. 12 shows internalization of anti-CD115 mAbs. From left to right, examples within the panel of anti-CD115 mAbs exhibiting no internalization, weak internalization, mid internalization, strong internalization and very strong internalization are depicted.

FIG. 13 shows conversion of anti-CD115 mAb ALM-423 to fully human antibodies.

FIG. 14 shows neutralization of CSF-1 binding to CD115 by fully human anti-CD115 mAbs.

FIG. 15 shows neutralization of pTyr formation on CD115 by fully human anti-CD115 mAbs.

FIG. 16 shows some anti-CD115 antibodies that are antagonists of CSF-1 induce p-tyr formation on CD115.

BRIEF DESCRIPTION OF THE SEQUENCES

SEQ ID NOs:1-108 are polynucleotide sequences encoding VH regions of the anti-CD115 antibodies listed in Table 2.

SEQ ID NOs:109-216 are amino acid sequences of VH regions of the anti-CD115 antibodies listed in Table 2.

SEQ ID NOs:217-324 are polynucleotide sequences encoding VL regions of the anti-CD115 antibodies listed in Table 2.

SEQ ID NOs:325-432 are amino acid sequences of VL regions of the anti-CD115 antibodies listed in Table 2.

SEQ ID NO:433 is an IgG specific primer.

SEQ ID NO:434 is an Igλ specific primer.

SEQ ID NO:435 is an Igκ specific primer.

SEQ ID NOs:436-543 are amino acid sequences of the VHCDR1 of the anti-CD115 antibodies listed in Table 2.

SEQ ID NOs:544-651 are polynucleotide sequences encoding the VHCDR1 of the anti-CD115 antibodies listed in Table 2.

SEQ ID NOs:652-759 are amino acid sequences of the VLCDR1 of the anti-CD115 antibodies listed in Table 2.

SEQ ID NOs:760-867 are polynucleotide sequences encoding the VLCDR1 of the anti-CD115 antibodies listed in Table 2.

SEQ ID NOs:868-975 are amino acid sequences of the VHCDR2 of the anti-CD115 antibodies listed in Table 2.

SEQ ID NOs:976-1083 are polynucleotide sequences encoding the VHCDR2 of the anti-CD115 antibodies listed in Table 2.

SEQ ID NOs:1084-1191 are amino acid sequences of the VLCDR2 of the anti-CD115 antibodies listed in Table 2.

SEQ ID NOs:1192-1299 are polynucleotide sequences encoding the VLCDR2 of the anti-CD115 antibodies listed in Table 2.

SEQ ID NOs:1300-1407 are amino acid sequences of the VHCDR3 of the anti-CD115 antibodies listed in Table 2.

SEQ ID NOs:1408-1515 are polynucleotide sequences encoding the VHCDR3 of the anti-CD115 antibodies listed in Table 2.

SEQ ID NOs:1516-1623 are amino acid sequences of the VLCDR3 of the anti-CD115 antibodies listed in Table 2.

SEQ ID NOs:1624-1731 are polynucleotide sequences encoding the VLCDR3 of the anti-CD115 antibodies listed in Table 2.

DETAILED DESCRIPTION

The present disclosure relates to anti-CD115 antibodies. Ablexis has used its proprietary AlivaMab® Mouse technology (See WO 2010/039900 and WO 2011/123708, incorporated herein in their entirety) to generate panels of monoclonal antibodies (mAbs) against human CD115. Antibodies that potently neutralize CD115 signaling induced by CSF-1 were identified within the panel of CD115 AlivaMab® antibodies. In one embodiment, anti-CD115 AlivaMab® antibodies potently neutralize CD115 signaling induced by IL-34. In one embodiment, anti-CD115 AlivaMab® antibodies that potently neutralize CD115 signaling induced by both CSF-1 and IL-34. CD115 (colony-stimulating factor 1 receptor, CSF1R, C-FMS) is a member of the receptor tyrosine kinase superfamily. For a review of CD115 biology, refer to Stanley and Chitu, Cold Spring Harb. Perspect. Biol. 2014 Jun. 2; 6(6).

Embodiments of the invention pertain to the use of anti-CD115 antibodies, or antigen-binding fragments thereof, for the diagnosis, assessment and treatment of diseases and disorders associated with CD115, CSF-1 and/or IL-34 or aberrant expression thereof. The subject antibodies are used in the treatment or prevention of neoplasms and/or the treatment or prevention of autoimmune and/or inflammatory diseases, among other diseases.

Portions of variable regions from the AlivaMab® antibodies may include all or a combination of the complementarity determining regions (CDRs) of the VH and/or VL. The variable regions may be formatted with constant regions, either native or modified for various desired effector functions, in a standard antibody structure (two heavy chains with two light chains). The variable regions may also be formatted as multi-specific antibodies, e.g., bispecific antibodies binding to two different epitopes on CD115 or to two different antigens, one of which is CD115. The variable regions may also be formatted as antibody fragments, e.g., single-domain antibodies comprising a single VH or VL, Fabs or Fab′2. The antibodies may also be used as antibody-drug conjugates, or carry other additions such as small molecule toxins, biologic toxins, cytokines, oligopeptides, or RNAs to increase therapeutic modality and/or increase safety.

The practice of the present invention will employ, unless indicated specifically to the contrary, conventional methods of virology, immunology, microbiology, molecular biology and recombinant DNA techniques within the skill of the art, many of which are described below for the purpose of illustration. Such techniques are explained fully in the literature. See, e.g., Current Protocols in Molecular Biology or Current Protocols in Immunology, John Wiley & Sons, New York, N.Y. (2009); Ausubel et al., Short Protocols in Molecular Biology, 3rd ed., Wiley & Sons, 1995; Sambrook and Russell, Molecular Cloning: A Laboratory Manual (3rd Edition, 2001); Maniatis et al., Molecular Cloning: A Laboratory Manual (1982); DNA Cloning: A Practical Approach, vol. I & II (D. Glover, ed.); Oligonucleotide Synthesis (N. Gait, ed., 1984); Nucleic Acid Hybridization (B. Hames & S. Higgins, eds., 1985); Transcription and Translation (B. Hames & S. Higgins, eds., 1984); Animal Cell Culture (R. Freshney, ed., 1986); Perbal, A Practical Guide to Molecular Cloning (1984) and other like references.

Before describing certain embodiments in detail, it is to be understood that this invention is not limited to particular compositions or biological systems, which can vary. It is also to be understood that the terminology used herein is for the purpose of describing particular illustrative embodiments only, and is not intended to be limiting. The terms used in this specification generally have their ordinary meaning in the art, within the context of this invention and in the specific context where each term is used. Certain terms are discussed below or elsewhere in the specification, to provide additional guidance to the practitioner in describing the compositions and methods of the invention and how to make and use them. The scope and meaning of any use of a term will be apparent from the specific context in which the term is used. As such, the definitions set forth herein are intended to provide illustrative guidance in ascertaining particular embodiments of the invention, without limitation to particular compositions or biological systems.

As used in the present disclosure and the appended claims, the singular forms “a,” “an” and “the” include plural references unless the content clearly dictates otherwise.

Throughout the present disclosure and the appended claims, unless the context requires otherwise, the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element or group of elements but not the exclusion of any other element or group of elements.

The terms “antibody” and “immunoglobulin” (Ig) are used interchangeably herein. An antibody may be either membrane bound or secreted. As used herein, the term encompasses not only intact, or “whole”, polyclonal or monoclonal antibodies, but also fragments thereof (such as single-variable domain (VH, VL or combination thereof) antibodies, Fab, Fab′, F(ab′)2, Fv), single chain (ScFv), synthetic variants thereof, naturally occurring variants, fusion proteins comprising an antibody portion with an antigen-binding fragment of the required specificity, humanized antibodies, chimeric antibodies, and any other modified configuration of the immunoglobulin molecule that comprises an antigen-binding site or fragment (epitope recognition site) of the required specificity.

Antibody, or Ig, molecules are typically comprised of two identical heavy chains and two identical light chains linked together through disulfide bonds. Both heavy chains (IgH) and light chains (IgL) contain a variable (V) region or domain and a constant (C) region or domain. The portion of the IgH locus encoding the V region comprises multiple copies of variable (V), diversity (D), and joining (J) gene segments. The portion of the IgL loci encoding the V region comprises multiple copies of V and J gene segments. The V region encoding portion of the IgH and IgL loci undergo gene segment rearrangement, e.g., different combinations of a V, (D) and J gene segments arrange to form the IgH and IgL variable regions, to develop diverse antigen specificity in antibodies. Each variable region comprises three complementarity-determining regions (CDRs) interspersed between the less variable framework regions (FRs). The heavy chain comprises VHCDR1, VHCDR2, and VHCDR3. The light chain comprises VLCDR1, VLCDR2, and VLCDR3. The secreted form of the IgH C region is made up of three C domains, CH1, CH2, CH3, optionally CH4 (CO, and a hinge region except for Cμ, which lacks a hinge region. The membrane-bound form of the IgH C region also has membrane and intra-cellular domains. The IgH constant region determines the isotype of the antibody, e.g. IgM, IgD, IgG1, IgG2, IgG3, IgG4, IgA and IgE. It will be appreciated that non-human mammals, such as an AlivaMab® Mouse, encoding multiple Ig isotypes will be able to undergo isotype class switching. There are two types of human IgL, Igκ and Igλ.

The term “antigen-binding fragment” as used herein refers to a polypeptide fragment that contains at least one CDR of an immunoglobulin heavy and/or light chain that binds to CD115. In this regard, an antigen-binding fragment of the antibodies may comprise 1, 2, 3, 4, 5, or all 6 CDRs of a VH and VL sequence set forth herein from anti-CD115 antibodies described herein. An antigen-binding fragment of the CD115-specific antibodies described herein is capable of binding to CD115. In certain embodiments, an antigen-binding fragment or an antibody comprising an antigen-binding fragment, prevents or inhibits CSF-1 and/or IL-34 binding to CD115 and subsequent signaling events. In other embodiments, an anti-CD115 antibody, or an antigen-binding fragment thereof, prevents signaling events mediated by CD115 by preventing dimerization of CD115, including dimerization that is induced by CSF-1 or IL-34 binding or that may happen spontaneously under certain conditions of expression CD115. In certain embodiments, the antigen-binding fragment binds specifically to and/or inhibits or modulates the biological activity of human CD115.

In certain embodiments, antibodies and antigen-binding fragments thereof as described herein include a heavy chain and a light chain CDR set, respectively interposed between a heavy chain and a light chain framework region (FR) set that provide conformational support to the CDRs and define the spatial relationship of the CDRs relative to each other. As used herein, the term “CDR set” refers to the three hypervariable regions of a heavy or light chain V region. Proceeding from the N terminus of a heavy or light chain, these regions are denoted as “CDR1,” “CDR2,” and “CDR3” respectively. An antigen-binding site, therefore, includes six CDRs, comprising the CDR set from each of a heavy and a light chain V region.

A “Fab” domain or fragment comprises the N-terminal portion of the IgH, which includes the V region and the CH1 domain of the IgH, and the entire IgL. A “F(ab′)₂” domain comprises the Fab domain and a portion of the hinge region, wherein the 2 IgH are linked together via disulfide linkage in the middle hinge region. Both the Fab and F(ab′)₂ are “antigen-binding fragments.” The C-terminal portion of the IgH, comprising the CH2 and CH3 domains, is the “Fc” domain. The Fc domain is the portion of the Ig recognized by cell receptors, such as the FcR, and to which the complement-activating protein, C1q, binds. The lower hinge region, which is encoded in the 5′ portion of the CH2 exon, provides flexibility within the antibody for binding to FcR receptors. An “Fv” fragment includes a non-covalent VH::VL heterodimer including an antigen-binding site. In certain embodiments, single chain Fv (scFv) antibodies are contemplated. A scFv is a covalently linked VH::VL heterodimer which is expressed from a gene fusion including VH- and VL-encoding genes linked by a peptide-encoding linker (Huston et al. (1988) Proc. Nat. Acad. Sci. USA 85(16):5879-5883).

Where bispecific antibodies are to be used, these may be conventional bispecific antibodies, which can be manufactured in a variety of ways (Holliger, P. and Winter G. Current Opinion Biotechnol. 4, 446-449 (1993)), e.g., prepared chemically or from hybrid hybridomas, or may be any of the bispecific antibody fragments mentioned above.

As used herein “chimeric antibody” refers to an antibody encoded by a polynucleotide sequence containing polynucleotide sequences from two or more species, e.g., human and mouse.

As used herein “chimeric Ig chain” refers to an Ig heavy chain or an Ig light chain encoded by a polynucleotide sequence containing polynucleotide sequences from two or more species, e.g., human and mouse. For example, a chimeric Ig heavy chain may comprise a human VH domain, DH domain, JH domain, CH1 domain, and upper hinge region and mouse CH2 and CH3 domains. In one embodiment, the middle hinge region is mouse. In one embodiment, the middle hinge region is human. In one embodiment, the middle hinge region is chimeric.

“Polypeptide,” “peptide” or “protein” are used interchangeably herein to describe a chain of amino acids that are linked together by chemical bonds. A polypeptide or protein may be an IgH, IgL, V domain, C domain, or an antibody.

The strength, or affinity of immunological binding interactions can be expressed in terms of the dissociation constant (K_(D)) of the interaction, wherein a smaller K_(D) represents a greater affinity. Immunological binding properties of selected polypeptides can be quantified using methods well known in the art. One such method entails measuring the rates of antigen-binding site/antigen complex formation and dissociation, wherein those rates depend on the concentrations of the complex partners, the affinity of the interaction, and on geometric parameters that equally influence the rate in both directions. Thus, both the “on rate constant” (K_(on)) and the “off rate constant” (K_(off)) can be determined by calculation of the concentrations and the actual rates of association and dissociation. The ratio of K_(off)/K_(on) enables cancellation of all parameters not related to affinity, and is thus equal to the dissociation constant, K_(D). See, generally, Davies et al. (1990) Annual Rev. Biochem. 59:439-473.

“Polynucleotide” refers to a chain of nucleic acids that are linked together by chemical bonds. Polynucleotides include, but are not limited to, DNA, cDNA, RNA, mRNA, and gene sequences and segments. Polynucleotides may be isolated from a living source such as a eukaryotic cell, prokaryotic cell or virus, or may be derived through in vitro manipulation by using standard techniques of molecular biology, or by DNA synthesis, or by a combination of a number of techniques.

As used herein, the term “vector” refers to a nucleic acid molecule into which another nucleic acid fragment can be integrated without loss of the vector's ability to replicate. Vectors may originate from a virus, a plasmid or the cell of a higher organism. Vectors are utilized to introduce foreign or recombinant DNA into a host cell, wherein the vector is replicated.

A polynucleotide agent can be contained in a vector, which can facilitate manipulation of the polynucleotide, including introduction of the polynucleotide into a target cell. The vector can be a cloning vector, which is useful for maintaining the polynucleotide, or can be an expression vector, which contains, in addition to the polynucleotide, regulatory elements useful for expressing the polynucleotide and, where the polynucleotide encodes an RNA, for expressing the encoded RNA in a particular cell, either for subsequent translation of the RNA into a polypeptide or for subsequent trans regulatory activity by the RNA in the cell. An expression vector can contain the expression elements necessary to achieve, for example, sustained transcription of the encoding polynucleotide, or the regulatory elements can be operatively linked to the polynucleotide prior to its being cloned into the vector.

An expression vector (or the polynucleotide) generally contains or encodes a promoter sequence, which can provide constitutive or, if desired, inducible or tissue specific or developmental stage specific expression of the encoding polynucleotide, a poly-A recognition sequence, and a ribosome recognition site or internal ribosome entry site, or other regulatory elements such as an enhancer, which can be tissue specific. The vector also can contain elements required for replication in a prokaryotic or eukaryotic host system or both, as desired. Such vectors, which include plasmid vectors and viral vectors such as bacteriophage, baculovirus, retrovirus, lentivirus, adenovirus, vaccinia virus, alpha virus and adeno-associated virus vectors, are well known and can be purchased from a commercial source (Promega, Madison Wis.; Stratagene, La Jolla Calif.; GIBCO/BRL, Gaithersburg Md.) or can be constructed by one skilled in the art (see, for example, Meth. Enzymol., Vol. 185, Goeddel, ed. (Academic Press, Inc., 1990); Jolly, Canc. Gene Ther. 1:51-64, 1994; Flotte, J. Bioenerg. Biomemb 25:37-42, 1993; Kirshenbaum et al., J. Clin. Invest 92:381-387, 1993; each of which is incorporated herein by reference).

The term “construct” as used herein refers to a sequence of DNA artificially constructed by genetic engineering, recombineering or synthesis. In one embodiment, the DNA constructs are linearized prior to recombination. In another embodiment, the DNA constructs are not linearized prior to recombination.

The terms “inhibit”, “neutralize”, and “antagonize” are used interchangeably herein and encompass anti-CD115 antibodies that block, inhibit, and/or decrease the activity of CD115. Examples of CD115 activity include kinase function and ligand binding, e.g., binding to CSF-1 and/or IL-34.

The term “treating” with regard to a subject, refers to improving at least one symptom of the subject's disease or disorder. Treating includes curing, improving, or at least partially ameliorating the disease or disorder.

As used herein, the term “disorder” refers to, and is used interchangeably with, the terms disease, condition, or illness.

The term “pharmaceutically acceptable carrier” refers generally to any material (e.g., carrier, excipient, or stabilizer) that may accompany a therapeutic agent and is nontoxic to the subject or patient being exposed thereto.

The term “administering,” as used herein, refers to any mode of transferring, delivering, introducing, or transporting a pharmaceutical composition or other agent, such as an anti-CD115 antibody, to a subject. Such modes include oral administration, topical contact, intravenous, intraperitoneal, intramuscular, intranasal, or subcutaneous administration.

The term “inhibit” or “neutralize” or “block” may relate generally to the ability of one or more anti-CD115 antibodies of the invention to decrease a biological activity of CD115, such as intracellular signaling and/or ligand binding. The inhibition/blocking of CSF-1 and/or IL-34 to CD115 preferably reduces or alters the normal level or type of cell signaling that occurs when CSF-1 and/or IL-34 binds to CD115 without inhibition or blocking. Inhibition and blocking are also intended to include any measurable decrease in the binding of CSF-1 and/or IL-34 to CD115 when in contact with an anti CD115 antibody as disclosed herein as compared to the ligand not in contact with an anti CD115 antibody, e.g., the blocking of CSF-1 and/or IL-34 to CD115 by at least about a 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% decrease, including all integers in between. In one embodiment, a neutralizing anti-CD115 antibody inhibits binding of CSF-1 and/or IL-34 to CD115 by at least about a 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% decrease, including all integers in between.

An antibody, or antigen-binding fragment thereof, is said to “specifically bind,” “immunologically bind,” and/or is “immunologically reactive” to CD115 if it reacts at a detectable level (within, for example, an ELISA assay) with CD115, and does not react detectably with unrelated polypeptides under similar conditions. Antibodies are considered to specifically bind to a target polypeptide when the binding affinity is at least 1×10⁻⁷ M or, preferably, at least 1×10⁻⁸ M. In one embodiment, the antibody, or antigen-binding fragment thereof, specifically binds human CD115.

Each embodiment in this specification is to be applied mutatis mutandis to every other embodiment unless expressly stated otherwise.

Standard techniques may be used for recombinant DNA, oligonucleotide synthesis, and tissue culture and transformation (e.g., electroporation, lipofection). Enzymatic reactions and purification techniques may be performed according to manufacturer's specifications or as commonly accomplished in the art or as described herein. These and related techniques and procedures may be generally performed according to conventional methods well known in the art and as described in various general and more specific references that are cited and discussed throughout the present specification. Unless specific definitions are provided, the nomenclature utilized in connection with, and the laboratory procedures and techniques of, molecular biology, analytical chemistry, synthetic organic chemistry, and medicinal and pharmaceutical chemistry described herein are those well-known and commonly used in the art. Standard techniques may be used for recombinant technology, molecular biological, microbiological, chemical syntheses, chemical analyses, pharmaceutical preparation, formulation, and delivery, and treatment of patients.

CD115

CD115 is expressed by a variety of cells, including, but not limited to, hematopoietic stem cells (HSCs); myeloid cells, including monocytes, macrophages, osteoclasts, dendritic cells, and microglia; neural progenitor cells; and epithelial cells, including Paneth cells (Stanley and Chitu, Cold Spring Harb Perspect Biol 2014; 6:a021857). Dysregulation of CD115, and/or its ligands, is associated with proliferative diseases and disorders (e.g., neoplasms, tumors and metastases), as well as immunological and neurological diseases and disorders, making it an important therapeutic target.

Anti-CD115 Antibodies

AlivaMab® Mouse anti-CD115 antibodies were generated using both AlivaMab® Mouse Kappa mice and AlivaMab® Mouse Lambda mice (also referred to herein interchangeably as AlivaMab® Kappa Mice and AlivaMab® Lambda Mice, respectively). Antibodies produced by AlivaMab® Kappa Mice comprise a chimeric immunoglobulin heavy (IgH) chain and a human immunoglobulin kappa (Igκ) light chain. Antibodies produced by AlivaMab® Lambda Mice comprise a chimeric IgH chain and a human immunoglobulin lambda (Igλ) light chain. The chimeric IgH chain of the AlivaMab® Mouse antibodies comprises a human variable region comprising a human variable heavy (VH) domain, a human diversity heavy (DH) domain, and a human joining heavy (JH) domain, a human constant heavy 1 (CH1) domain, a human upper hinge region (except for Cμ, which is naturally missing an upper hinge region), a mouse middle hinge region, a mouse CH2 domain, and a mouse CH3 domain. Upon identification of a lead candidate antibody, e.g., an anti-CD115 antibody, the human heavy chain variable region is readily appended to a fully human constant region while maintaining the antigen-binding characteristics of the parent chimeric antibody that were developed in vivo in the AlivaMab® Mouse. In one embodiment, the human heavy chain variable region, CH1 and, optionally, upper hinge region of the chimeric antibody are appended to human hinge, a human CH2 domain and a human CH3 domain in order to produce a fully human antibody.

Accordingly, in one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, of the invention is chimeric. In one embodiment, the chimeric anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a chimeric IgH chain and a human Igκ chain. In one embodiment, the chimeric anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a chimeric IgH chain and a human Igλ chain. In one embodiment, the chimeric anti-CD115 antibody is human and mouse. In one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, of the invention is human. In one embodiment, the human anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a human IgH chain and a human Igκ chain. In one embodiment, the human anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a human IgH chain and a human Igλ chain. In one embodiment, the isotype of the anti-CD115 antibody is selected from IgM, IgD, IgG1, IgG2, IgG3, IgG4, IgA and IgE. In one embodiment, the isotype of the anti-CD115 antibody is selected from IgG1, IgG2, IgG3, and IgG4.

In one embodiment, the anti-CD115 antibody binds an Fc receptor (FcR) selected from an FcγR, an FcεR, and an FcαR. In one embodiment, the anti-CD115 antibody binds an FcγR selected from FcγRI (CD64), FcγRII (CD32), and FcγRIII (CD16), including isoforms thereof. In one embodiment, the Fc region of the anti-CD115 antibody comprises a mutation so that it preferentially binds a particular FcγR (see, e.g., U.S. Pat. No. 6,737,056 and U.S. 2015/0031862).

In one aspect of the invention, the CDRs of an anti-CD115 antibody, or antigen-binding fragment thereof, may be mixed and matched between the CDRs of antibody clones described herein. In one embodiment, an anti-CD115 antibody, or antigen-binding fragment thereof, comprises a VHCDR1 comprising any one of SEQ ID NOs:436-543, a VHCDR2 comprising any one of SEQ ID NOs:868-975, and a VHCDR3 comprising any one of SEQ ID NOs:1300-1407. In one embodiment, the VHCDR1, VHCDR2 and VHCDR3 are selected from three different anti-CD115 clones disclosed herein. In one embodiment, the VHCDR1, VHCDR2 and VHCDR3 are selected from two different anti-CD115 clones disclosed herein.

In one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a VLCDR1 comprising any one of SEQ ID NOs:652-759, a VLCDR2 comprising any one of SEQ ID NOs:1084-1191, and a VLCDR3 comprising any one of SEQ ID NOs:1516-1623. In one embodiment, the VLCDR1, VLCDR2 and VLCDR3 are selected from three different anti-CD115 clones disclosed herein. In one embodiment, the VLCDR1, VLCDR2 and VLCDR3 are selected from two different anti-CD115 clones disclosed herein.

In one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, comprises 1) comprises a VHCDR1 comprising any one of SEQ ID NOs: 436-543, a VHCDR2 comprising any one of SEQ ID NOs: 868-975, and a VHCDR3 comprising any one of SEQ ID NOs: 300-1407, and 2) a VLCDR1 comprising any one of SEQ ID NOs: 652-759, a VLCDR2 comprising any one of SEQ ID NOs: 1084-1191, and a VLCDR3 comprising any one of SEQ ID NOs: 1516-1623.

In one aspect of the invention, the CDRs of an anti-CD115 antibody, or antigen-binding fragment thereof, are from the same anti-CD115 antibody clone disclosed herein. In one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a VHCDR1, a VHCDR2 and a VHCDR3 from the same anti-CD115 clone disclosed herein. In one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a VHCDR1, a VHCDR2, and a VHCDR3 of a VH selected from any one of SEQ ID NOs:109-216. In one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a VHCDR1, a VHCDR2, and a VHCDR3 comprising the corresponding sequences listed in Table 3.

Accordingly, in one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a VHCDR1, a VHCDR2, and a VHCDR3 selected from: SEQ ID NOs:436, 868, and 1300; SEQ ID NOs:437, 869, and 1301; SEQ ID NOs:438, 870, and 1302; SEQ ID NOs:439, 871, and 1303; SEQ ID NOs:440, 872, and 1304; SEQ ID NOs:441, 873, and 1305; SEQ ID NOs:442, 874, and 1306; SEQ ID NOs:443, 875, and 1307; SEQ ID NOs:444, 876, and 1308; SEQ ID NOs:445, 877, and 1309; SEQ ID NOs:446, 878, and 1310; SEQ ID NOs:447, 879, and 1311; SEQ ID NOs:448, 880, and 1312; SEQ ID NOs:449, 881, and 1313; SEQ ID NOs:450, 882, and 1314; SEQ ID NOs:451, 883, and 1315; SEQ ID NOs:452, 884, and 1316; SEQ ID NOs:453, 885, and 1317; SEQ ID NOs:454, 886, and 1318; SEQ ID NOs:455, 887, and 1319; SEQ ID NOs:456, 888, and 1320; SEQ ID NOs:457, 889, and 1321; SEQ ID NOs:458, 890, and 1322; SEQ ID NOs:459, 891, and 1323; SEQ ID NOs:460, 892, and 1324; SEQ ID NOs:461, 893, and 1325; SEQ ID NOs:462, 894, and 1326; SEQ ID NOs:463, 895, and 1327; SEQ ID NOs:464, 896, and 1328; SEQ ID NOs:465, 897, and 1329; SEQ ID NOs:466, 898, and 1330; SEQ ID NOs:467, 899, and 1331; SEQ ID NOs:468, 900, and 1332; SEQ ID NOs:469, 901, and 1333; SEQ ID NOs:470, 902, and 1334; SEQ ID NOs:471, 903, and 1335; SEQ ID NOs:472, 904, and 1336; SEQ ID NOs:473, 905, and 1337; SEQ ID NOs:474, 906, and 1338; SEQ ID NOs:475, 907, and 1339; SEQ ID NOs:476, 908, and 1340; SEQ ID NOs:477, 909, and 1341; SEQ ID NOs:478, 910, and 1342; SEQ ID NOs:479, 911, and 1343; SEQ ID NOs:480, 912, and 1344; SEQ ID NOs:481, 913, and 1345; SEQ ID NOs:482, 914, and 1346; SEQ ID NOs:483, 915, and 1347; SEQ ID NOs:484, 916, and 1348; SEQ ID NOs:485, 917, and 1349; SEQ ID NOs:486, 918, and 1350; SEQ ID NOs:487, 919, and 1351; SEQ ID NOs:488, 920, and 1352; SEQ ID NOs:489, 921, and 1353; SEQ ID NOs:490, 922, and 1354; SEQ ID NOs:491, 923, and 1355; SEQ ID NOs:492, 924, and 1356; SEQ ID NOs:493, 925, and 1357; SEQ ID NOs:494, 926, and 1358; SEQ ID NOs:495, 927, and 1359; SEQ ID NOs:496, 928, and 1360; SEQ ID NOs:497, 929, and 1361; SEQ ID NOs:498, 930, and 1362; SEQ ID NOs:499, 931, and 1363; SEQ ID NOs:500, 932, and 1364; SEQ ID NOs:501, 933, and 1365; SEQ ID NOs:502, 934, and 1366; SEQ ID NOs:503, 935, and 1367; SEQ ID NOs:504, 936, and 1368; SEQ ID NOs:505, 937, and 1369; SEQ ID NOs:506, 938, and 1370; SEQ ID NOs:507, 939, and 1371; SEQ ID NOs:508, 940, and 1372; SEQ ID NOs:509, 941, and 1373; SEQ ID NOs:510, 942, and 1374; SEQ ID NOs:511, 943, and 1375; SEQ ID NOs:512, 944, and 1376; SEQ ID NOs:513, 945, and 1377; SEQ ID NOs:514, 946, and 1378; SEQ ID NOs:515, 947, and 1379; SEQ ID NOs:516, 948, and 1380; SEQ ID NOs:517, 949, and 1381; SEQ ID NOs:518, 950, and 1382; SEQ ID NOs:519, 951, and 1383; SEQ ID NOs:520, 952, and 1384; SEQ ID NOs:521, 953, and 1385; SEQ ID NOs:522, 954, and 1386; SEQ ID NOs:523, 955, and 1387; SEQ ID NOs:524, 956, and 1388; SEQ ID NOs:525, 957, and 1389; SEQ ID NOs:526, 958, and 1390; SEQ ID NOs:527, 959, and 1391; SEQ ID NOs:528, 960, and 1392; SEQ ID NOs:529, 961, and 1393; SEQ ID NOs:530, 962, and 1394; SEQ ID NOs:531, 963, and 1395; SEQ ID NOs:532, 964, and 1396; SEQ ID NOs:533, 965, and 1397; SEQ ID NOs:534, 966, and 1398; SEQ ID NOs:535, 967, and 1399; SEQ ID NOs:536, 968, and 1400; SEQ ID NOs:537, 969, and 1401; SEQ ID NOs:538, 970, and 1402; SEQ ID NOs:539, 971, and 1403; SEQ ID NOs:540, 972, and 1404; SEQ ID NOs:541, 973, and 1405; SEQ ID NOs:542, 974, and 1406; and SEQ ID NOs:543, 975, and 1407.

In one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a VLCDR1, a VLCDR2 and a VLCDR3 from the same anti-CD115 clone disclosed herein. In one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a VLCDR1, a VLCDR2, and a VLCDR3 of a VL selected from any one of SEQ ID NOs:325-432. In one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a VLCDR1, a VLCDR2, and a VLCDR3 comprising the corresponding sequences listed in Table 3.

Accordingly, in one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a VLCDR1, a VLCDR2, and a VLCDR3 selected from: SEQ ID NOs:652, 1084, and 1516; SEQ ID NOs:653, 1085, and 1517; SEQ ID NOs:654, 1086, and 1518; SEQ ID NOs:655, 1087, and 1519; SEQ ID NOs:656, 1088, and 1520; SEQ ID NOs:657, 1089, and 1521; SEQ ID NOs:658, 1090, and 1522; SEQ ID NOs:659, 1091, and 1523; SEQ ID NOs:660, 1092, and 1524; SEQ ID NOs:661, 1093, and 1525; SEQ ID NOs:662, 1094, and 1526; SEQ ID NOs:663, 1095, and 1527; SEQ ID NOs:664, 1096, and 1528; SEQ ID NOs:665, 1097, and 1529; SEQ ID NOs:666, 1098, and 1530; SEQ ID NOs:667, 1099, and 1531; SEQ ID NOs:668, 1100, and 1532; SEQ ID NOs:669, 1101, and 1533; SEQ ID NOs:670, 1102, and 1534; SEQ ID NOs:671, 1103, and 1535; SEQ ID NOs:672, 1104, and 1536; SEQ ID NOs:673, 1105, and 1537; SEQ ID NOs:674, 1106, and 1538; SEQ ID NOs:675, 1107, and 1539; SEQ ID NOs:676, 1108, and 1540; SEQ ID NOs:677, 1109, and 1541; SEQ ID NOs:678, 1110, and 1542; SEQ ID NOs:679, 1111, and 1543; SEQ ID NOs:680, 1112, and 1544; SEQ ID NOs:681, 1113, and 1545; SEQ ID NOs:682, 1114, and 1546; SEQ ID NOs:683, 1115, and 1547; SEQ ID NOs:684, 1116, and 1548; SEQ ID NOs:685, 1117, and 1549; SEQ ID NOs:686, 1118, and 1550; SEQ ID NOs:687, 1119, and 1551; SEQ ID NOs:688, 1120, and 1552; SEQ ID NOs:689, 1121, and 1553; SEQ ID NOs:690, 1122, and 1554; SEQ ID NOs:691, 1123, and 1555; SEQ ID NOs:692, 1124, and 1556; SEQ ID NOs:693, 1125, and 1557; SEQ ID NOs:694, 1126, and 1558; SEQ ID NOs:695, 1127, and 1559; SEQ ID NOs:696, 1128, and 1560; SEQ ID NOs:697, 1129, and 1561; SEQ ID NOs:698, 1130, and 1562; SEQ ID NOs:699, 1131, and 1563; SEQ ID NOs:700, 1132, and 1564; SEQ ID NOs:701, 1133, and 1565; SEQ ID NOs:702, 1134, and 1566; SEQ ID NOs:703, 1135, and 1567; SEQ ID NOs:704, 1136, and 1568; SEQ ID NOs:705, 1137, and 1569; SEQ ID NOs:706, 1138, and 1570; SEQ ID NOs:707, 1139, and 1571; SEQ ID NOs:708, 1140, and 1572; SEQ ID NOs:709, 1141, and 1573; SEQ ID NOs:710, 1142, and 1574; SEQ ID NOs:711, 1143, and 1575; SEQ ID NOs:712, 1144, and 1576; SEQ ID NOs:713, 1145, and 1577; SEQ ID NOs:714, 1146, and 1578; SEQ ID NOs:715, 1147, and 1579; SEQ ID NOs:716, 1148, and 1580; SEQ ID NOs:717, 1149, and 1581; SEQ ID NOs:718, 1150, and 1582; SEQ ID NOs:719, 1151, and 1583; SEQ ID NOs:720, 1152, and 1584; SEQ ID NOs:721, 1153, and 1585; SEQ ID NOs:722, 1154, and 1586; SEQ ID NOs:723, 1155, and 1587; SEQ ID NOs:724, 1156, and 1588; SEQ ID NOs:725, 1157, and 1589; SEQ ID NOs:726, 1158, and 1590; SEQ ID NOs:727, 1159, and 1591; SEQ ID NOs:728, 1160, and 1592; SEQ ID NOs:729, 1161, and 1593; SEQ ID NOs:730, 1162, and 1594; SEQ ID NOs:731, 1163, and 1595; SEQ ID NOs:732, 1164, and 1596; SEQ ID NOs:733, 1165, and 1597; SEQ ID NOs:734, 1166, and 1598; SEQ ID NOs:735, 1167, and 1599; SEQ ID NOs:736, 1168, and 1600; SEQ ID NOs:737, 1169, and 1601; SEQ ID NOs:738, 1170, and 1602; SEQ ID NOs:739, 1171, and 1603; SEQ ID NOs:740, 1172, and 1604; SEQ ID NOs:741, 1173, and 1605; SEQ ID NOs:742, 1174, and 1606; SEQ ID NOs:743, 1175, and 1607; SEQ ID NOs:744, 1176, and 1608; SEQ ID NOs:745, 1177, and 1609; SEQ ID NOs:746, 1178, and 1610; SEQ ID NOs:747, 1179, and 1611; SEQ ID NOs:748, 1180, and 1612; SEQ ID NOs:749, 1181, and 1613; SEQ ID NOs:750, 1182, and 1614; SEQ ID NOs:751, 1183, and 1615; SEQ ID NOs:752, 1184, and 1616; SEQ ID NOs:753, 1185, and 1617; SEQ ID NOs:754, 1186, and 1618; SEQ ID NOs:755, 1187, and 1619; SEQ ID NOs:756, 1188, and 1620; SEQ ID NOs:757, 1189, and 1621; SEQ ID NOs:758, 1190, and 1622; and SEQ ID NOs:759, 1191, and 1623.

In another aspect of the invention, the CDRs of an anti-CD115 antibody, or antigen-binding fragment thereof, are selected from the corresponding VH and VL of a single clone described herein. In one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, comprises 1) a VHCDR1, a VHCDR2, and a VHCDR3 selected from the VHCDR1, VHCDR2 and VHCDR3 of one VH selected from any one of SEQ ID NOs: 109-216 and 2) a VLCDR1, a VLCDR2, and a VLCDR3 selected from the VLCDR1, VLCDR2 and VLCDR3 of one VL selected from any one of SEQ ID NOs:325-432. In one embodiment, an anti-CD115 antibody, or antigen-binding fragment thereof, comprises a VHCDR1, a VHCDR2, a VHCDR3, a VLCDR1, a VLCDR2, and a VLCDR3 within the corresponding VH and VL amino acid sequences of a single clone as set forth in Table 3.

Accordingly, in one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a VHCDR1, a VHCDR2, a VHCDR3, a VLCDR1, a VLCDR2, and a VLCDR3 selected from: SEQ ID NOs:436, 868, 1300, 652, 1084, and 1516; SEQ ID NOs:437, 869, 1301, 653, 1085, and 1517; SEQ ID NOs:438, 870, 1302, 654, 1086, and 1518; SEQ ID NOs:439, 871, 1303, 655, 1087, and 1519; SEQ ID NOs:440, 872, 1304, 656, 1088, and 1520; SEQ ID NOs:441, 873, 1305, 657, 1089, and 1521; SEQ ID NOs:442, 874, 1306, 658, 1090, and 1522; SEQ ID NOs:443, 875, 1307, 659, 1091, and 1523; SEQ ID NOs:444, 876, 1308, 660, 1092, and 1524; SEQ ID NOs:445, 877, 1309, 661, 1093, and 1525; SEQ ID NOs:446, 878, 1310, 662, 1094, and 1526; SEQ ID NOs:447, 879, 1311, 663, 1095, and 1527; SEQ ID NOs:448, 880, 1312, 664, 1096, and 1528; SEQ ID NOs:449, 881, 1313, 665, 1097, and 1529; SEQ ID NOs:450, 882, 1314, 666, 1098, and 1530; SEQ ID NOs:451, 883, 1315, 667, 1099, and 1531; SEQ ID NOs:452, 884, 1316, 668, 1100, and 1532; SEQ ID NOs:453, 885, 1317, 669, 1101, and 1533; SEQ ID NOs:454, 886, 1318, 670, 1102, and 1534; SEQ ID NOs:455, 887, 1319, 671, 1103, and 1535; SEQ ID NOs:456, 888, 1320, 672, 1104, and 1536; SEQ ID NOs:457, 889, 1321, 673, 1105, and 1537; SEQ ID NOs:458, 890, 1322, 674, 1106, and 1538; SEQ ID NOs:459, 891, 1323, 675, 1107, and 1539; SEQ ID NOs:460, 892, 1324, 676, 1108, and 1540; SEQ ID NOs:461, 893, 1325, 677, 1109, and 1541; SEQ ID NOs:462, 894, 1326, 678, 1110, and 1542; SEQ ID NOs:463, 895, 1327, 679, 1111, and 1543; SEQ ID NOs:464, 896, 1328, 680, 1112, and 1544; SEQ ID NOs:465, 897, 1329, 681, 1113, and 1545; SEQ ID NOs:466, 898, 1330, 682, 1114, and 1546; SEQ ID NOs:467, 899, 1331, 683, 1115, and 1547; SEQ ID NOs:468, 900, 1332, 684, 1116, and 1548; SEQ ID NOs:469, 901, 1333, 685, 1117, and 1549; SEQ ID NOs:470, 902, 1334, 686, 1118, and 1550; SEQ ID NOs:471, 903, 1335, 687, 1119, and 1551; SEQ ID NOs:472, 904, 1336, 688, 1120, and 1552; SEQ ID NOs:473, 905, 1337, 689, 1121, and 1553; SEQ ID NOs:474, 906, 1338, 690, 1122, and 1554; SEQ ID NOs:475, 907, 1339, 691, 1123, and 1555; SEQ ID NOs:476, 908, 1340, 692, 1124, and 1556; SEQ ID NOs:477, 909, 1341, 693, 1125, and 1557; SEQ ID NOs:478, 910, 1342, 694, 1126, and 1558; SEQ ID NOs:479, 911, 1343, 695, 1127, and 1559; SEQ ID NOs:480, 912, 1344, 696, 1128, and 1560; SEQ ID NOs:481, 913, 1345, 697, 1129, and 1561; SEQ ID NOs:482, 914, 1346, 698, 1130, and 1562; SEQ ID NOs:483, 915, 1347, 699, 1131, and 1563; SEQ ID NOs:484, 916, 1348, 700, 1132, and 1564; SEQ ID NOs:485, 917, 1349, 701, 1133, and 1565; SEQ ID NOs:486, 918, 1350, 702, 1134, and 1566; SEQ ID NOs:487, 919, 1351, 703, 1135, and 1567; SEQ ID NOs:488, 920, 1352, 704, 1136, and 1568; SEQ ID NOs:489, 921, 1353, 705, 1137, and 1569; SEQ ID NOs:490, 922, 1354, 706, 1138, and 1570; SEQ ID NOs:491, 923, 1355, 707, 1139, and 1571; SEQ ID NOs:492, 924, 1356, 708, 1140, and 1572; SEQ ID NOs:493, 925, 1357, 709, 1141, and 1573; SEQ ID NOs:494, 926, 1358, 710, 1142, and 1574; SEQ ID NOs:495, 927, 1359, 711, 1143, and 1575; SEQ ID NOs:496, 928, 1360, 712, 1144, and 1576; SEQ ID NOs:497, 929, 1361, 713, 1145, and 1577; SEQ ID NOs:498, 930, 1362, 714, 1146, and 1578; SEQ ID NOs:499, 931, 1363, 715, 1147, and 1579; SEQ ID NOs:500, 932, 1364, 716, 1148, and 1580; SEQ ID NOs:501, 933, 1365, 717, 1149, and 1581; SEQ ID NOs:502, 934, 1366, 718, 1150, and 1582; SEQ ID NOs:503, 935, 1367, 719, 1151, and 1583; SEQ ID NOs:504, 936, 1368, 720, 1152, and 1584; SEQ ID NOs:505, 937, 1369, 721, 1153, and 1585; SEQ ID NOs:506, 938, 1370, 722, 1154, and 1586; SEQ ID NOs:507, 939, 1371, 723, 1155, and 1587; SEQ ID NOs:508, 940, 1372, 724, 1156, and 1588; SEQ ID NOs:509, 941, 1373, 725, 1157, and 1589; SEQ ID NOs:510, 942, 1374, 726, 1158, and 1590; SEQ ID NOs:511, 943, 1375, 727, 1159, and 1591; SEQ ID NOs:512, 944, 1376, 728, 1160, and 1592; SEQ ID NOs:513, 945, 1377, 729, 1161, and 1593; SEQ ID NOs:514, 946, 1378, 730, 1162, and 1594; SEQ ID NOs:515, 947, 1379, 731, 1163, and 1595; SEQ ID NOs:516, 948, 1380, 732, 1164, and 1596; SEQ ID NOs:517, 949, 1381, 733, 1165, and 1597; SEQ ID NOs:518, 950, 1382, 734, 1166, and 1598; SEQ ID NOs:519, 951, 1383, 735, 1167, and 1599; SEQ ID NOs:520, 952, 1384, 736, 1168, and 1600; SEQ ID NOs:521, 953, 1385, 737, 1169, and 1601; SEQ ID NOs:522, 954, 1386, 738, 1170, and 1602; SEQ ID NOs:523, 955, 1387, 739, 1171, and 1603; SEQ ID NOs:524, 956, 1388, 740, 1172, and 1604; SEQ ID NOs:525, 957, 1389, 741, 1173, and 1605; SEQ ID NOs:526, 958, 1390, 742, 1174, and 1606; SEQ ID NOs:527, 959, 1391, 743, 1175, and 1607; SEQ ID NOs:528, 960, 1392, 744, 1176, and 1608; SEQ ID NOs:529, 961, 1393, 745, 1177, and 1609; SEQ ID NOs:530, 962, 1394, 746, 1178, and 1610; SEQ ID NOs:531, 963, 1395, 747, 1179, and 1611; SEQ ID NOs:532, 964, 1396, 748, 1180, and 1612; SEQ ID NOs:533, 965, 1397, 749, 1181, and 1613; SEQ ID NOs:534, 966, 1398, 750, 1182, and 1614; SEQ ID NOs:535, 967, 1399, 751, 1183, and 1615; SEQ ID NOs:536, 968, 1400, 752, 1184, and 1616; SEQ ID NOs:537, 969, 1401, 753, 1185, and 1617; SEQ ID NOs:538, 970, 1402, 754, 1186, and 1618; SEQ ID NOs:539, 971, 1403, 755, 1187, and 1619; SEQ ID NOs:540, 972, 1404, 756, 1188, and 1620; SEQ ID NOs:541, 973, 1405, 757, 1189, and 1621; SEQ ID NOs:542, 974, 1406, 758, 1190, and 1622; and SEQ ID NOs:543, 975, 1407, 759, 1191, and 1623.

In one embodiment, an anti-CD115 antibody, or antigen-binding fragment thereof, comprises a VH comprising any one of SEQ ID NOs: 109-216. In one embodiment, an anti-CD115 antibody, or antigen-binding fragment thereof, comprises a VL comprising any one of SEQ ID NOs:325-432. In one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a corresponding VH and VL of a single clone as set forth in Table 3.

Accordingly, in one embodiment, an anti-CD115 antibody, or an antigen-binding fragment thereof, comprises a VH and a VL selected from: SEQ ID NOs:109 and 325; SEQ ID NOs:110 and 326; SEQ ID NOs:111 and 327; SEQ ID NOs:112 and 328; SEQ ID NOs:113 and 329; SEQ ID NOs:114 and 330; SEQ ID NOs:115 and 331; SEQ ID NOs:116 and 332; SEQ ID NOs:117 and 333; SEQ ID NOs:118 and 334; SEQ ID NOs:119 and 335; SEQ ID NOs:120 and 336; SEQ ID NOs:121 and 337; SEQ ID NOs:122 and 338; SEQ ID NOs:123 and 339; SEQ ID NOs:124 and 340; SEQ ID NOs:125 and 341; SEQ ID NOs:126 and 342; SEQ ID NOs:127 and 343; SEQ ID NOs:128 and 344; SEQ ID NOs:129 and 345; SEQ ID NOs:130 and 346; SEQ ID NOs:131 and 347; SEQ ID NOs:132 and 348; SEQ ID NOs:133 and 349; SEQ ID NOs:134 and 350; SEQ ID NOs:135 and 351; SEQ ID NOs:136 and 352; SEQ ID NOs:137 and 353; SEQ ID NOs:138 and 354; SEQ ID NOs:139 and 355; SEQ ID NOs:140 and 356; SEQ ID NOs:141 and 357; SEQ ID NOs:142 and 358; SEQ ID NOs:143 and 359; SEQ ID NOs:144 and 360; SEQ ID NOs:145 and 361; SEQ ID NOs:146 and 362; SEQ ID NOs:147 and 363; SEQ ID NOs:148 and 364; SEQ ID NOs:149 and 365; SEQ ID NOs:150 and 366; SEQ ID NOs:151 and 367; SEQ ID NOs:152 and 368; SEQ ID NOs:153 and 369; SEQ ID NOs:154 and 370; SEQ ID NOs:155 and 371; SEQ ID NOs:156 and 372; SEQ ID NOs:157 and 373; SEQ ID NOs:158 and 374; SEQ ID NOs:159 and 375; SEQ ID NOs:160 and 376; SEQ ID NOs:161 and 377; SEQ ID NOs:162 and 378; SEQ ID NOs:163 and 379; SEQ ID NOs:164 and 380; SEQ ID NOs:165 and 381; SEQ ID NOs:166 and 382; SEQ ID NOs:167 and 383; SEQ ID NOs:168 and 384; SEQ ID NOs:169 and 385; SEQ ID NOs:170 and 386; SEQ ID NOs:171 and 387; SEQ ID NOs:172 and 388; SEQ ID NOs:173 and 389; SEQ ID NOs:174 and 390; SEQ ID NOs:175 and 391; SEQ ID NOs:176 and 392; SEQ ID NOs:177 and 393; SEQ ID NOs:178 and 394; SEQ ID NOs:179 and 395; SEQ ID NOs:180 and 396; SEQ ID NOs:181 and 397; SEQ ID NOs:182 and 398; SEQ ID NOs:183 and 399; SEQ ID NOs:184 and 400; SEQ ID NOs:185 and 401; SEQ ID NOs:186 and 402; SEQ ID NOs:187 and 403; SEQ ID NOs:188 and 404; SEQ ID NOs:189 and 405; SEQ ID NOs:190 and 406; SEQ ID NOs:191 and 407; SEQ ID NOs:192 and 408; SEQ ID NOs:193 and 409; SEQ ID NOs:194 and 410; SEQ ID NOs:195 and 411; SEQ ID NOs:196 and 412; SEQ ID NOs:197 and 413; SEQ ID NOs:198 and 414; SEQ ID NOs:199 and 415; SEQ ID NOs:200 and 416; SEQ ID NOs:201 and 417; SEQ ID NOs:202 and 418; SEQ ID NOs:203 and 419; SEQ ID NOs:204 and 420; SEQ ID NOs:205 and 421; SEQ ID NOs:206 and 422; SEQ ID NOs:207 and 423; SEQ ID NOs:208 and 424; SEQ ID NOs:209 and 425; SEQ ID NOs:210 and 426; SEQ ID NOs:211 and 427; SEQ ID NOs:212 and 428; SEQ ID NOs:213 and 429; SEQ ID NOs:214 and 430; SEQ ID NOs:215 and 431; and SEQ ID NOs:216 and 432.

In one embodiment, an anti-CD115 antibody is a whole antibody. In one embodiment, an anti-CD115 antibody is a single chain antibody. In one embodiment, an anti-CD115 antibody is a scFv. In one embodiment, an anti-CD115 antibody is a Fab. In one embodiment, an anti-CD115 antibody is a F(ab′)₂. In one embodiment, an anti-CD115 antibody is a Fv.

In one embodiment, an anti-CD115 antibody is a bispecific antibody. In one embodiment, a bispecific anti-CD115 antibody specifically recognizes two different epitopes of CD115. In one embodiment, a bispecific anti-CD115 comprises a first CDR set comprising the VHCDR1, VHCDR2, VHCDR3, VLCDR1, VLCDR2, and VLCDR3 from a first anti-CD115 antibody clone disclosed herein and a second CDR set comprising the VHCDR1, VHCDR2, VHCDR3, VLCDR1, VLCDR2, and VLCDR3 of a second anti-CD115 antibody clone disclosed herein. In one embodiment, a bispecific anti-CD115 comprises a corresponding first VH and first VL of a first anti-CD115 antibody clone disclosed herein and a corresponding second VH and second VL of a second anti-CD115 antibody clone disclosed herein. In one embodiment, a bispecific anti-CD115 antibody specifically recognizes CD115 and another antigen.

Neutralizing Anti-CD115 Antibodies

One aspect of the present invention provides anti-CD115 antibodies, and antigen-binding fragments thereof, that are CD115 antagonists. In one embodiment, an antagonist anti-CD115 antibody, or antigen-binding fragment thereof, neutralizes or inhibits one or more ligands of CD115 from binding CD115. In one embodiment, an antagonist anti-CD115 antibody, or antigen-binding fragment thereof, inhibits CSF-1 from binding CD115. In one embodiment, an antagonist anti-CD115 antibody, or antigen-binding fragment thereof, inhibits IL-34 from binding CD115. In one embodiment, an antagonist anti-CD115 antibody, or antigen-binding fragment thereof, inhibits CSF-1 and IL-34 from binding CD115. In one embodiment, an antagonist anti-CD115 antibody, or antigen-binding fragment thereof, prevents dimerization of CD115, including dimerization that is induced by CSF-1 or IL-34 binding or that may happen spontaneously under certain conditions of expression CD115. In one embodiment, an antagonist anti-CD115 antibody, or antigen-binding fragment thereof, inhibits CD115 signaling. In one embodiment, an antagonist anti-CD115 antibody, or antigen-binding fragment thereof, inhibits ligand-induced phosphorylation of CD115.

Polynucleotides

One aspect of the present invention provides a polynucleotide sequence that encodes an anti-CD115 antibody, or antigen-binding fragment thereof, disclosed herein. In one embodiment, the polynucleotide is a recombinant polynucleotide. In one embodiment, the polynucleotide is cDNA.

In one embodiment, a polynucleotide sequence encodes a CDR of an anti-CD115 antibody disclosed herein. In one embodiment, the polynucleotide comprises a VHCDR1 polynucleotide sequence selected from any one of SEQ ID NOs:544-651. In one embodiment, the polynucleotide comprises a VHCDR2 polynucleotide sequence selected from any one of SEQ ID NOs:976-1083. In one embodiment, the polynucleotide comprises a VHCDR3 polynucleotide sequence selected from any one of SEQ ID NOs:1408-1515. In one embodiment, the polynucleotide comprises a VLCDR1 polynucleotide sequence selected from any one of SEQ ID NOs:760-867. In one embodiment, the polynucleotide comprises a VLCDR2 polynucleotide sequence selected from any one of SEQ ID NOs:1192-1299. In one embodiment, the polynucleotide comprises a VLCDR3 polynucleotide sequence selected from any one of SEQ ID NOs: 1624-1731.

In one embodiment, a polynucleotide sequence encodes a VH of an anti-CD115 antibody disclosed herein. In one embodiment, the polynucleotide comprises a VH polynucleotide sequence selected from any one of SEQ ID NOs:1-108. In one embodiment, a polynucleotide sequence encodes a VL of an anti-CD115 antibody disclosed herein. In one embodiment, the polynucleotide comprises a VL polynucleotide sequence selected from any one of SEQ ID NOs:217-324. In one embodiment, a polynucleotide sequence encodes a VH and a VL of an anti-CD115 antibody disclosed herein.

One embodiment of the invention provides a vector comprising a polynucleotide sequence encoding an anti-CD115 antibody, or an antigen-binding fragment thereof, disclosed herein. In one embodiment, the vector is an expression vector. In one embodiment, the vector is a cloning vector. One embodiment of the invention provides a host cell comprising the vector.

Methods of Use

The AlivaMab® antibodies against CD115, and in particular fully human antibodies incorporating all or portions of the heavy chain and light chain variable regions from the AlivaMab® antibodies, may have utility for the treatment of human disease including, but not limited to, diseases in oncology and autoimmunity and inflammation. As the understanding of CD115 biology and disease association becomes better known, it is expected that opportunities for human clinical therapeutic indications may expand. In particular, oncological, immunological, and neurological diseases and disorders are contemplated.

An anti-CD115 antibody, or antigen-binding fragment thereof, disclosed herein may be used in research, diagnostic, and/or therapeutic methods. In one embodiment, an anti-CD115 antibody, or antigen-binding fragment thereof, disclosed herein is used to treat diseases and disorders associated with CD115, CSF-1 and/or IL-34. In one embodiment, an anti-CD115 antibody, or antigen-binding fragment thereof, disclosed herein is used to treat diseases and disorders associated with CD115 overexpression. In one embodiment, an anti-CD115 antibody, or antigen-binding fragment thereof, disclosed herein is used to treat diseases and disorders associated with CSF-1 overexpression. In one embodiment, an anti-CD115 antibody, or antigen-binding fragment thereof, disclosed herein is used to treat diseases and disorders associated with IL-34 overexpression. In one embodiment, an anti-CD115 antibody, or antigen-binding fragment thereof, disclosed herein is used to treat diseases and disorders associated with aberrant CD115 signaling.

Embodiments of the invention pertain to the use of anti-CD115 antibodies, or antigen-binding fragments thereof, for the diagnosis and prognosis of diseases and disorders associated with CD115, CSF-1 and/or IL-34 or aberrant expression thereof.

Modified Anti-CD115 Antibodies and Compositions

Anti-CD115 antibodies of the present invention, and antigen-binding fragments and variants thereof, may also be conjugated or operably linked to another compound (e.g., therapeutic agent, label, or tag), referred to herein as a conjugate. The conjugate may be a cytotoxic agent, a chemotherapeutic agent, a cytokine, an anti-angiogenic agent, a tyrosine kinase inhibitor, a toxin, a radioisotope, or other therapeutically active agent. Chemotherapeutic agents, cytokines, anti-angiogenic agents, tyrosine kinase inhibitors, and other therapeutic agents are contemplated. In one embodiment, the antibody is conjugated or operably linked to a toxin, including but not limited to small molecule toxins and enzymatically active toxins of bacterial, fungal, plant, animal or synthetic origin, including fragments and/or variants thereof.

There are many linking groups known in the art for making antibody conjugates, including, for example, those disclosed in U.S. Pat. No. 5,208,020 or EP Patent 0425235 B1, and Chari et al., Cancer Research 52: 127-131 (1992). The linking groups include disulfide groups, thioether groups, acid labile groups, photolabile groups, peptidase labile groups, or esterase labile groups, as disclosed in the above-identified patents, disulfide and thioether groups being preferred.

The present invention further relates to pharmaceutical compositions and methods of use. The pharmaceutical compositions of the present invention include an antibody, or fragment thereof, in a pharmaceutically acceptable carrier. Pharmaceutical compositions may be administered in vivo for the treatment or prevention of a disease or disorder. Furthermore, pharmaceutical compositions comprising an antibody, or a fragment thereof, of the present invention may include one or more agents for use in combination, or may be administered in conjunction with one or more agents. Agents for use in combination with an anti-CD115 antibody disclosed herein include, but are not limited to cytotoxic agents, chemotherapeutic agents, cytokines, anti-angiogenic agents, tyrosine kinase inhibitors, toxins, and radioisotopes.

The present invention also provides kits relating to any of the antibodies, or fragments thereof, and/or methods described herein. Kits of the present invention may include diagnostic or therapeutic agents. A kit of the present invention may further provide instructions for use of a composition or antibody and packaging. A kit of the present invention may include devices, reagents, containers or other components. Furthermore, a kit of the present invention may also require the use of an apparatus, instrument or device, including a computer.

EXAMPLES

The Examples below utilize a CD115 phosphorylation assay in order to detect phospho-CD115. SR cells (confirmed CD115 expression by FACS) were serum starved overnight (1% FBS). Cells were treated with M-CSF or IL-34 in the presence of CD115 mAbs for 30 minutes on ice. Cells were lysed in buffer containing phosphatase and protease inhibitors. Lysates were run on R&D systems p-MCSFR DUOSET, which is an ELISA comprising validated phospho-CD115-specific antibody pairs. Exemplary results from a p-CD115 (MCSFR) ELISA using SR cells are shown in FIGS. 1 and 3 .

Example 1 Preparation of Monoclonal Antibodies to Cd 115

Monoclonal antibodies were prepared in accordance with a general method as described in “Antibodies: A Laboratory Manual” (Harlow and Lane 1988 CSH Press). Eight-week old AlivaMab® Kappa Mice and eight-week old AlivaMab® Lambda Mice mice were immunized using a RIMMS protocol. 50 ug of human CD115 extracellular domain (Sino Biological, China 10161-H08H) was mixed with 40 ul (first immunization), 20 ul (immunizations 2-4) or 0 ul (final immunization) Gerbu MM adjuvant (C-C Biotech, Valley Center, Calif. #3001-6030) and PBS was added to a final volume of 100 ul. The 50 ug mixture was injected in 20 ul portions in 5 locations per mouse; right and left flanks and right and left shoulder/armpit subcutaneously, and the remaining 20 ul intraperitoneally. This was done 5 times per mouse on days, 1, 4, 7, 9, and 11. On Day 14 mice were sacrificed and terminal materials were collected. Spleens and lymph nodes were prepared and fused with CRL-2016 myeloma cells (ATCC) using a PEG based method as generally described in “Antibodies: A Laboratory Manual” (Harlow and Lane 1988 CSH Press) to establish hybridomas.

Hybridomas were grown in 384-well tissue culture plates and supernatants from individual wells were screened by ELISA for production of antibodies recognizing huCD115. Positive wells were then transferred to 48-well plates, expanded, and supernatants were collected for huCD115 binding confirmation by ELISA. Positive supernatants were also counter-screened against a non-related histidine-tagged protein. Fifty to sixty hybridoma lines each from AlivaMab® Kappa Mice and AlivaMab® Lambda Mice confirmed to bind CD115 specifically by ELISA were picked at random and single-cell cloned into 96-well plates. One hundred and eight (108) hybridoma lines were cloned. They were grown into colonies and the supernatant from these individual colonies was screened by ELISA to re-confirm monoclonal antibody binding to huCD115. These supernatants were then screened by FACS to confirm binding to native CD115 on OCI-AML5 cells (DSMZ #ACC-247, Table 1 shows results for select antibodies, and FIG. 7 ). Seventy-five hybridoma clones were confirmed to produce mAb that bound to CD115-expressing OCI-AML5 cells (FIG. 5 ).

TABLE 1 Summary of Screening for Binding to CD115 on cell Surface FACS HYBRIDOMA Binding CCL-247A + CCK-423A + CCK-415A + CCK-416A + CCK-541A + CCK-424A + CCK-507A + CCK-461A + CCK-421A + CCL-331A + CCK-422A + CCK-437A + CCL-327A + CCK-522A + CCL-309A + CCL-321A + CCL-332A + CCL-217A + CCL-328A + CCL-221A + CCK-402A + CCL-238A + CCL-245A + CCK-417A + CCL-215A + CCL-346A + CCL-213A + CCL-205A + CCL-216A + CCL-211A + CCL-204A + CCL-325A + CCL-337A + CCL-249A +

Example 2 Sequences of Anti-CD115 VH and VL

Total RNA was extracted from hybridomas producing anti-CD115 monoclonal antibodies using the Qiagen RNeasy Mini kit (Cat No. 74104), followed by 5′ RACE, using the 5′ RACE system kit (Life Technologies, US cat #18734-058) with the following 3′ gene specific primers IgG 5′-GGTTCGGGGAAGTAGTCCTTGACC-3′ (SEQ ID NO:433) IgL 5′-CTGTAGCTTCTGTGGGACTTCCACTGCTC-3′ (SEQ ID NO:434) IgK 5′-CCGATTGGAGGGCGTTATCCAC-3′ (SEQ ID NO:435). RACE products were gel purified and cloned into pCR4-TOPO using TOPO TA cloning kit for sequencing with One Shot Top 10 chemically competent E. coli (Life Technologies, US Cat #K4575-01). Sequencing of vector containing colonies was performed by Sequetech (Mountain View, Calif.) using M13F or M13R sequencing primers. The reported nucleotide sequences start at the first nucleotide in the first codon for the amino terminal amino acid in framework 1. The reported polypeptide sequences are based on an in silico translation of the nucleic acid sequence and start at the first amino acid at the amino terminus of framework 1.

TABLE 2 Anti-CD115 mAb Amino Acid (aa) and Polynucleotide (nt) Sequences VH VHCDR1 VHCDR2 VHCDR3 VL VLCDR1 VLCDR2 VLCDR3 aa nt aa nt aa nt aa nt aa nt aa nt aa nt aa nt SEQ SEQ SEQ SEQ SEQ SEQ SEQ SEQ SEQ SEQ SEQ SEQ SEQ SEQ SEQ SEQ ID ID ID ID ID ID ID ID ID ID ID ID ID ID ID ID Clone NO: NO: NO: NO: NO: NO: NO: NO: NO: NO: NO: NO: NO: NO: NO: NO: CCK-401A 109 1 436 544 868 976 1300 1408 325 217 652 760 1084 1192 1516 1624 CCK-402A 110 2 437 545 869 977 1301 1409 326 218 653 761 1085 1193 1517 1625 CCK-406A 111 3 438 546 870 978 1302 1410 327 219 654 762 1086 1194 1518 1626 CCK-407A 112 4 439 547 871 979 1303 1411 328 220 655 763 1087 1195 1519 1627 CCK-408A 113 5 440 548 872 980 1304 1412 329 221 656 764 1088 1196 1520 1628 CCK-410A 114 6 441 549 873 981 1305 1413 330 222 657 765 1089 1197 1521 1629 CCK-412A 115 7 442 550 874 982 1306 1414 331 223 658 766 1090 1198 1522 1630 CCK-414A 116 8 443 551 875 983 1307 1415 332 224 659 767 1091 1199 1523 1631 CCK-415A 117 9 444 552 876 984 1308 1416 333 225 660 768 1092 1200 1524 1632 CCK-416A 118 10 445 553 877 985 1309 1417 334 226 661 769 1093 1201 1525 1633 CCK-417A 119 11 446 554 878 986 1310 1418 335 227 662 770 1094 1202 1526 1634 CCK-418A 120 12 447 555 879 987 1311 1419 336 228 663 771 1095 1203 1527 1635 CCK-421A 121 13 448 556 880 988 1312 1420 337 229 664 772 1096 1204 1528 1636 CCK-422A 122 14 449 557 881 989 1313 1421 338 230 665 773 1097 1205 1529 1637 CCK-423A 123 15 450 558 882 990 1314 1422 339 231 666 774 1098 1206 1530 1638 CCK-424A 124 16 451 559 883 991 1315 1423 340 232 667 775 1099 1207 1531 1639 CCK-425A 125 17 452 560 884 992 1316 1424 341 233 668 776 1100 1208 1532 1640 CCK-434A 126 18 453 561 885 993 1317 1425 342 234 669 777 1101 1209 1533 1641 CCK-435A 127 19 454 562 886 994 1318 1426 343 235 670 778 1102 1210 1534 1642 CCK-436A 128 20 455 563 887 995 1319 1427 344 236 671 779 1103 1211 1535 1643 CCK-437A 129 21 456 564 888 996 1320 1428 345 237 672 780 1104 1212 1536 1644 CCK-455A 130 22 457 565 889 997 1321 1429 346 238 673 781 1105 1213 1537 1645 CCK-456A 131 23 458 566 890 998 1322 1430 347 239 674 782 1106 1214 1538 1646 CCK-458A 132 24 459 567 891 999 1323 1431 348 240 675 783 1107 1215 1539 1647 CCK-459A 133 25 460 568 892 1000 1324 1432 349 241 676 784 1108 1216 1540 1648 CCK-460A 134 26 461 569 893 1001 1325 1433 350 242 677 785 1109 1217 1541 1649 CCK-461A 135 27 462 570 894 1002 1326 1434 351 243 678 786 1110 1218 1542 1650 CCK-464A 136 28 463 571 895 1003 1327 1435 352 244 679 787 1111 1219 1543 1651 CCK-465A 137 29 464 572 896 1004 1328 1436 253 245 680 788 1112 1220 1544 1652 CCK-467A 138 30 465 573 897 1005 1329 1437 354 246 681 789 1113 1221 1545 1653 CCK-468A 139 31 466 574 898 1006 1330 1438 355 247 682 790 1114 1222 1546 1654 CCK-501A 140 32 467 575 899 1007 1331 1439 356 248 683 791 1115 1223 1547 1655 CCK-503A 141 33 468 576 900 1008 1332 1440 357 249 684 792 1116 1224 1548 1656 CCK-505A 142 34 469 577 901 1009 1333 1441 358 250 685 793 1117 1225 1549 1657 CCK-507A 143 35 470 578 902 1010 1334 1442 359 251 686 794 1118 1226 1550 1658 CCK-511A 144 36 471 579 903 1011 1335 1443 360 252 687 795 1119 1227 1551 1659 CCK-513A 145 37 472 580 904 1012 1336 1444 361 253 688 796 1120 1228 1552 1660 CCK-514A 146 38 473 581 905 1013 1337 1445 362 254 689 797 1121 1229 1553 1661 CCK-516A 147 39 474 582 906 1014 1338 1446 363 255 690 798 1122 1230 1554 1662 CCK-519A 148 40 475 583 907 1015 1339 1447 364 256 691 799 1123 1231 1555 1663 CCK-522A 149 41 476 584 908 1016 1340 1448 365 257 692 800 1124 1232 1556 1664 CCK-525A 150 42 477 585 909 1017 1341 1449 366 258 693 801 1125 1233 1557 1665 CCK-526A 151 43 478 586 910 1018 1342 1450 367 259 694 802 1126 1234 1558 1666 CCK-533A 152 44 479 587 911 1019 1343 1451 368 260 695 803 1127 1235 1559 1667 CCK-539A 153 45 480 588 912 1020 1344 1452 369 261 696 804 1128 1236 1560 1668 CCK-541A 154 46 481 589 913 1021 1345 1453 370 262 697 805 1129 1237 1561 1669 CCK-542A 155 47 482 590 914 1022 1346 1454 371 263 698 806 1130 1238 1562 1670 CCK-543A 156 48 483 591 915 1023 1347 1455 372 264 699 807 1131 1239 1563 1671 CCL-201A 157 49 484 592 916 1024 1348 1456 373 265 700 808 1132 1240 1564 1672 CCL-203A 158 50 485 593 917 1025 1349 1457 374 266 701 809 1133 1241 1565 1673 CCL-204A 159 51 486 594 918 1026 1350 1458 375 267 702 810 1134 1242 1566 1674 CCL-205A 160 52 487 595 919 1027 1351 1459 376 268 703 811 1135 1243 1567 1675 CCL-206A 161 53 488 596 920 1028 1352 1460 377 269 704 812 1136 1244 1568 1676 CCL-207A 162 54 489 597 921 1029 1353 1461 378 270 705 813 1137 1245 1569 1677 CCL-208A 163 55 490 598 922 1030 1354 1462 379 271 706 814 1138 1246 1570 1678 CCL-209A 164 56 491 599 923 1031 1355 1463 380 272 707 815 1139 1247 1571 1679 CCL-211A 165 57 492 600 924 1032 1356 1464 381 273 708 816 1140 1248 1572 1680 CCL-212A 166 58 493 601 925 1033 1357 1465 382 274 709 817 1141 1249 1573 1681 CCL-213A 167 59 494 602 926 1034 1358 1466 383 275 710 818 1142 1250 1574 1682 CCL-215A 168 60 495 603 927 1035 1359 1467 384 276 711 819 1143 1251 1575 1683 CCL-216A 169 61 496 604 928 1036 1360 1468 385 277 712 820 1144 1252 1576 1684 CCL-217A 170 62 497 605 929 1037 1361 1469 386 278 713 821 1145 1253 1577 1685 CCL-218A 171 63 498 606 930 1038 1362 1470 387 279 714 822 1146 1254 1578 1686 CCL-220A 172 64 499 607 931 1039 1363 1471 388 280 715 823 1147 1255 1579 1687 CCL-221A 173 65 500 608 932 1040 1364 1472 389 281 716 824 1148 1256 1580 1688 CCL-223A 174 66 501 609 933 1041 1365 1473 390 282 717 825 1149 1257 1581 1689 CCL-225A 175 67 502 610 934 1042 1366 1474 391 283 718 826 1150 1258 1582 1690 CCL-226A 176 68 503 611 935 1043 1367 1475 392 284 719 827 1151 1259 1583 1691 CCL-229A 177 69 504 612 936 1044 1368 1476 393 285 720 828 1152 1260 1584 1692 CCL-231A 178 70 505 613 937 1045 1369 1477 394 286 721 829 1153 1261 1585 1693 CCL-235A 179 71 506 614 938 1046 1370 1478 395 287 722 830 1154 1262 1586 1694 CCL-238A 180 72 507 615 939 1047 1371 1479 396 288 723 831 1155 1263 1587 1695 CCL-245A 181 73 508 616 940 1048 1372 1480 397 289 724 832 1156 1264 1588 1696 CCL-247A 182 74 509 617 941 1049 1373 1481 398 290 725 833 1157 1265 1589 1697 CCL-249A 183 75 510 618 942 1050 1374 1482 399 291 726 834 1158 1266 1590 1698 CCL-252A 184 76 511 619 943 1051 1375 1483 400 292 727 835 1159 1267 1591 1699 CCL-253A 185 77 512 620 944 1052 1376 1484 401 293 728 836 1160 1268 1592 1700 CCL-255A 186 78 513 621 945 1053 1377 1485 402 294 729 837 1161 1269 1593 1701 CCL-301A 187 79 514 622 946 1054 1378 1486 403 295 730 838 1162 1270 1594 1702 CCL-303A 188 80 515 623 947 1055 1379 1487 404 296 731 839 1163 1271 1595 1703 CCL-305A 189 81 516 624 948 1056 1380 1488 405 297 732 840 1164 1272 1596 1704 CCL-309A 190 82 517 625 949 1057 1381 1489 406 298 733 841 1165 1273 1597 1705 CCL-310A 191 83 518 626 950 1058 1382 1490 407 299 734 842 1166 1274 1598 1706 CCL-311A 192 84 519 627 951 1059 1383 1491 408 300 735 843 1167 1275 1599 1707 CCL-312A 193 85 520 628 952 1060 1384 1492 409 301 736 844 1168 1276 1600 1708 CCL-313A 194 86 521 629 953 1061 1385 1493 410 302 737 845 1169 1277 1601 1709 CCL-314A 195 87 522 630 954 1062 1386 1494 411 303 738 846 1170 1278 1602 1710 CCL-315A 196 88 523 631 955 1063 1387 1495 412 304 739 847 1171 1279 1603 1711 CCL-320A 197 89 524 632 956 1064 1388 1496 413 305 740 848 1172 1280 1604 1712 CCL-321A 198 90 525 633 957 1065 1389 1497 414 306 741 849 1173 1281 1605 1713 CCL-322A 199 91 526 634 958 1066 1390 1498 415 307 742 850 1174 1282 1606 1714 CCL-324A 200 92 527 635 959 1067 1391 1499 416 308 743 851 1175 1283 1607 1715 CCL-325A 201 93 528 636 960 1068 1392 1500 417 309 744 852 1176 1284 1608 1716 CCL-327A 202 94 529 637 961 1069 1393 1501 418 310 745 853 1177 1285 1609 1717 CCL-328A 203 95 530 638 962 1070 1394 1502 419 311 746 854 1178 1286 1610 1718 CCL-329A 204 96 531 639 963 1071 1395 1503 420 312 747 855 1179 1287 1611 1719 CCL-331A 205 97 532 640 964 1072 1396 1504 421 313 748 856 1180 1288 1612 1720 CCL-332A 206 98 533 641 965 1073 1397 1505 422 314 749 857 1181 1289 1613 1721 CCL-333A 207 99 534 642 966 1074 1398 1506 423 315 750 858 1182 1290 1614 1799 CCL-335A 208 100 535 643 967 1075 1399 1507 424 316 751 859 1183 1291 1615 1723 CCL-337A 209 101 536 644 968 1076 1400 1508 425 317 752 860 1184 1292 1616 1724 CCL-338A 210 102 537 645 969 1077 1401 1509 426 318 753 861 1185 1293 1617 1725 CCL-339A 211 103 538 646 970 1078 1402 1510 427 319 754 862 1186 1294 1618 1726 CCL-340A 212 104 539 647 971 1079 1403 1511 428 320 755 863 1187 1295 1619 1727 CCL-341A 213 105 540 648 972 1080 1404 1512 429 321 756 864 1188 1296 1620 1728 CCL-344A 214 106 541 649 973 1081 1405 1513 430 322 757 865 1189 1297 1621 1729 CCL-346A 215 107 542 650 974 1082 1406 1514 431 323 758 866 1190 1298 1622 1730 CCL-349A 216 108 543 651 975 1083 1407 1515 432 324 759 867 1191 1299 1623 1731

Example 3 Epitope Binning

A competition ELISA was performed to establish competitive binding bins. ELISA plates were coated with 1 ug/ml huCD115 protein (Sino Biological, China 10161-H08H) and blocked with Superblock (Thermo Scientific #37518). After washing, wells were incubated with a mouse monoclonal antibody representing one of six unique competition bins and for some of which, exhibit different activities in blocking CSF-1 and/or IL-34 binding to CD115 (Table 7) (these mouse mAbs were generated by hybridoma by immunizing wild-type mice as described in Example 1 as part of a comparator CD115 antibody generation program as part of the first tests of the newly-created AlivaMab® Mouse technology). After 1 hour the wells were washed and incubated with individual clonal anti-huCD115 AlivaMab® hybridoma supernatants. After another hour the wells were washed and incubated with a specific secondary antibody that either recognized human kappa LC or human lambda LC depending on which AlivaMab® Mouse supernatants were being detected (Southern Biotech Goat X hu kappa LC #2061-05 or Bethyl Goat X hu lambda LC #A80-116P) and detected with Supersignal ELISA Pico Chemiluminescent substrate (Thermo Scientific—Product #37069) (Tables 5 and 6). Individual AlivaMab® Mouse antibodies that were able to bind in the presence of a mouse antibody are considered to be in a unique epitope bin from that particular mouse antibody. Individual AlivaMab® Mouse antibodies that were unable to bind in the presence of a mouse antibody are considered to be in the same epitope bin as that particular mouse antibody. In this way multiple epitope bins were defined for huCD115 binding antibodies (Tables 3 and 6).

TABLE 3 Multiple Epitope Bins IgGκ IgGλ TOTAL BIN 1 4 0 4 BIN 2 18 16 34 BIN 3 6 28 34 BIN 4 6 8 14 BIN 5 1 5 6 BIN 6 7 2 9 BIN 7 2 0 2 BIN 8 6 0 6

TABLE 4 Binning of AlivaMab Kappa Mouse Anti-CD115 mAbs 1A 1B 1C 1D 1E 3 4 5 522 505 417 462 511 526 542 519 412 402 503 435 437 401 406 Bin 1 TMR 95A 7 1 3 3 3 9 23 36 3 131 82 86 84 94 87 Bin 1.5 TMR 44B 24 10 19 23 2 3 10 12 110 126 89 75 78 93 88 Bin 1.7 TMR 24A 33 0 6 12 99 68 94 110 13 131 97 79 86 96 96 Bin 2 TMR 20A 34 53 110 93 77 92 7 6 70 145 95 85 95 104 103 Bin 3 TMR 35A 83 110 110 77 76 82 111 110 78 11 23 96 101 98 99 Bin 4 TMR 100A 67 111 113 89 91 84 76 118 91 147 96 17 51 106 109 NO COMP 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 1A 1B 455 458 522 585 417 462 422 424 461 421 TMR 95A 0 6 7 1 3 3 6 16 15 9 TMR 44B 28 17 24 10 19 23 31 53 41 55 TMR 24A −1 2 33 0 6 12 11 29 27 18 TMR 20A 58 22 34 53 110 93 107 98 110 104 TMR 35A 54 66 80 110 110 77 111 102 110 100 TMR 100A 79 79 67 111 113 89 111 98 110 99 NO COMP 100 100 100 100 100 100 100 100 100 100 1B 525 415 418 599 516 454 416 456 514 467 466 464 TMR 95A 11 11 10 19 20 29 21 27 42 46 34 57 TMR 44B 56 46 3 21 10 23 53 27 4 22 13 0 TMR 24A 13 31 35 51 39 37 37 42 53 58 58 39 TMR 20A 80 97 89 82 70 115 94 73 84 96 86 87 TMR 35A 88 96 82 85 82 110 107 64 75 83 100 85 TMR 100A 100 93 106 85 87 89 104 96 103 102 98 96 NO COMP 100 100 100 100 100 100 100 100 100 100 100 100 1C 1D 1E 511 526 460 465 429 418 425 542 519 541 549 468 412 TMR 95A 3 9 23 41 38 35 21 23 36 42 1 61 3 TMR 44B 2 3 48 8 45 60 6 10 12 15 2 24 110 TMR 24A 99 68 61 81 75 75 78 94 110 109 111 85 13 TMR 20A 77 92 85 78 84 91 4 7 6 34 59 53 70 TMR 35A 76 82 86 88 112 86 88 111 110 111 89 104 78 TMR 100A 91 84 94 92 107 94 98 76 118 93 100 95 91 NO COM 100 100 100 100 100 100 100 100 100 100 100 100 100 3 4 5 482 589 587 459 599 487 488 495 497 481 486 414 496 581 519 TMR 95A 131 82 74 77 97 84 68 86 84 94 87 86 81 91 77 TMR 44B 126 89 87 84 92 94 80 75 78 93 88 87 91 106 86 TMR 24A 131 97 106 86 112 86 74 79 86 96 96 92 87 95 90 TMR 20A 145 95 112 90 102 97 100 85 95 104 103 106 96 114 92 TMR 35A 11 23 7 3 4 6 34 96 101 98 99 91 92 106 89 TMR 100A 147 96 123 95 109 103 101 17 51 106 109 101 100 116 93 NO COM 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

TABLE 5 Epitope Competition Bins in Panels of anti-CD115 mAbs BIN 1 BIN 2 BIN 3 BIN 4 BIN 5 BIN 6 BIN 7 BIN 8 CCK CCK CCK CCK CCK CCK CCK CCK CCK CCL CCK CCK CCK CCK CCK CCK 522A 505A 417A 462A 511A 526A 542A 519A 412A 321A 402A 503A 43 5A 43 7A 401A 406A TMR 4413 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 TMR 24A 0 0 0 0 1 1 1 1 0 0 1 1 1 1 1 1 TMR 20A 0 0 1 1 1 1 0 0 1 1 1 1 1 1 1 1 TMR 35A 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 TMR 100A 1 1 1 1 1 1 1 1 1 1 1 1 0 0 1 1 NO COMP 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

TABLE 6 Anti-CD115 mAb Epitope Bins HYBRIDOMA BIN HYBRIDOMA BIN CCK-401A 5 CCL-201A 1C CCK-402A 3 CCL-203A 1C CCK-406A 5 CCL-204A 1C CCK-407A 3 CCL-205A 1C CCK-408A 3 CCL-206A 1B CCK-410A 1C CCL-207A 1C CCK-412A 1E CCL-208A 1D CCK-414A 5 CCL-209A 1D CCK-415A 1B CCL-211A 1C CCK-416A 1B CCL-212A 1B CCK-417A 1B CCL-213A 1B CCK-418A 1B CCL-215A 1C CCK-421A 1B CCL-216A 1C CCK-422A 1B CCL-217A 1C CCK-423A 1C CCL-218A 1B CCK-424A 1B CCL-220A 1C CCK-425A 1D CCL-221A 1E CCK-434A 1B CCL-223A 1C CCK-435A 4 CCL-225A 1B CCK-436A 5 CCL-226A 1C CCK-437A 4 CCL-229A 1B CCK-455A 1A CCL-231A 1E CCK-456A 1B CCL-235A 1B CCK-458A 1A CCL-238A 1C CCK-459A 3 CCL-245A 1C CCK-460A 1D CCL-247A 1C CCK-461A 1B CCL-249A 1C CCK-464A 1B CCL-252A 1B CCK-465A 1C CCL-253A 1C CCK-467A 1B CCL-255A 1C CCK-468A 1C CCL-301A 1D CCK-501A 5 CCL-303A 1C CCK-503A 3 CCL-305A 1D CCK-505A 1A CCL-309A 1E CCK-507A 3 CCL-310A 1C CCK-511A 1C CCL-311A 1B CCK-513A 5 CCL-312A 3 CCK-514A 1B CCL-313A 3 CCK-516A 1B CCL-314A 1B CCK-519A 1D CCL-315A 1B CCK-522A 1A CCL-320A 1B CCK-525A 1B CCL-321A 1E CCK-526A 1C CCL-322A 1C CCK-533A 3 CCL-324A 1B CCK-539A 1B CCL-325A 1C CCK-541A 1D CCL-327A 1D CCK-542A 1D CCL-328A 1D CCK-543A 1D CCL-329A 1C CCL-331A 1E CCL-332A 1C CCL-333A 1C CCL-335A 1B CCL-337A 1C CCL-338A 1B CCL-339A 1C CCL-340A 1C CCL-341A 1D CCL-344A 1D CCL-346A 1C CCL-349A 1B

Based on functional characterization of the bin-defining mouse mAbs, some antibodies within epitope bins 1A or 1C (defined by dual IL-34- and CSF-1-neutralizing mouse mAb, TMR24A) or bin 3 (defined by dual IL-34- and CSF-1-neutralizing mouse mAb, TMR35A) may neutralize P-TYR formation induced by both CSF-1 and IL-34 (FIG. 2 ). Some antibodies within epitope bin 1C (defined by only CSF-1-neutralizing and IL-34 non-neutralizing mouse mAb, TMR20A) may neutralize only CSF-1-induced P-TYR formation on CD115. However, some bin 3 mAbs may neutralize both IL-34 and CSF-1 induced P-TYR formation on CD115. As summarized in Table 7 below, some of the reference wild-type mouse mAbs can block both cytokines from different locations on the receptor (e.g., bin 1 and bin3), some mAbs block M-CSF while not blocking IL-34, none of the mAbs were agonists on their own, and the bin 3 epitope region appears to contain functional diversity (e.g., all 3 mAbs listed below exhibited different activity). Also of note is that mAb 20A slightly increased/enhanced the M-CSF signal (FIGS. 4A and 4B).

TABLE 7 Summary of anti-CD115 mAb Activity mAb Bin Blocks M-CSF Blocks IL-34 24A 1 +++ +++ 29A 1 +++ +++ 32B 1 +++ +++ 20A 2 Slight agonist NO 10B 3 +++ NO 35A 3 +++ +++ 47B 3 NO NO 40A 4 + NO 27A 4 + NO 19B 5 +++ NO  7B 6 NO NO 44B 6 NO NO

Example 4 Affinity Determination

Affinity was determined for 24 selected monoclonal hybridoma supernatants (Biosensor Tools, Salt Lake City, Utah). Binding kinetics were measured using a BioRad ProteOn XPR36 optical biosensor equipped with an anti-mouse IgG-Coated GLC sensor chip. Hybridoma supernatants were diluted 10-fold into running buffer and captured for 4 minutes on the anti-mouse IgG surface. Hu CD115 (Sino Biological, China #10161-H08H) was tested in duplicate using a 3-fold dilution series starting at 150 nM. The processed data were fit using a 1:1 interaction model that includes a mass-transport parameter (Scrubber2, Canberra Australia). Within the panel of AlivaMab® Mouse anti-CD115 antibodies, there are antibodies with KD values below a nanomolar and KD values in the low nanomolar range, and with fast k_(on) and slow k_(off) rates (Tables 8 and 9).

TABLE 8 Binding Kinetics of Anti-CD115 IgGλ mAbs mAb ka (M⁻¹s⁻¹) kd (s⁻¹) K_(D) (pM) 329 1.18 × 10⁵ 4.46 × 10⁻⁶ 38 310 5.06 × 10⁴ 4.35 × 10⁻⁶ 79 331 1.86 × 10⁵ 2.20 × 10⁻⁵ 118 215 8.53 × 10⁴ 1.83 × 10⁻⁵ 215 225 5.00 × 10⁴ 1.38 × 10⁻⁵ 277 340 7.41 × 10⁴ 2.72 × 10⁻⁵ 367 312 1.39 × 10⁵ 6.03 × 10⁻⁵ 435 206 5.90 × 10⁴ 2.92 × 10⁻⁵ 495 231 8.10 × 10⁴ 4.71 × 10⁻⁵ 578 249 1.49 × 10⁵ 8.91 × 10⁻⁵ 599 217 9.81 × 10⁴ 1.20 × 10⁻⁴ 1,220 313 7.36 × 10⁴ 9.09 × 10⁻⁵ 1,240 327 1.33 × 10⁵ 1.89 × 10⁻⁴ 1,410

TABLE 9 Binding Kinetics of Anti-CD115 IgGκ mAbs mAb ka (M⁻¹s⁻¹) kd (s⁻¹) K_(D) (pM) 418 1.33 × 10⁵ 2.11 × 10⁻⁵ 158 533 1.24 × 10⁵ 3.92 × 10⁻⁵ 317 412 1.58 × 10⁵ 5.94 × 10⁻⁴ 376 460 8.92 × 10⁵ 5.51 × 10⁻⁴ 618 467 2.30 × 10⁴ 1.48 × 10⁻⁵ 650 459 5.00 × 10⁴ 3.38 × 10⁻⁵ 680 519 9.00 × 10⁴ 7.71 × 10⁻⁵ 860 407 6.90 × 10⁴ 6.54 × 10⁻⁵ 950 541 2.67 × 10⁵ 3.74 × 10⁻⁴ 1,400 465 5.31 × 10⁵ 7.49 × 10⁻⁴ 1,410 456 2.70 × 10⁴ 5.30 × 10⁻⁵ 1,970 539 3.20 × 10⁴ 8.50 × 10⁻⁵ 2,700

Example 5 Internalization of Anti-CD115 Antibodies

Anti-CD115 antibodies were tested for their ability to internalize upon binding to native CD115 on the surface of OCI-AML5 cells (DSMZ #ACC-247). OCI-AML5 cells were treated with individual AlivaMab® Mouse anti-CD115 supernatants for 1 hour at 37° C. The cells were then transferred to ice and stained with a fluorescently labeled anti-CD115 mAb known to be able to bind CD115 in the presence of bound test antibody (either Biolegend Rat x Hu-CD115-PE #6393 or CCK533A conjugated with Dylight488 Pierce #46403). Detection of fluorescent signal was then measured using a BD FACScalibur instrument. Cells that gave a strong fluorescent signal are considered to be non-internalizers for that individual test anti-CD115 mAb. Cells that are measured to have weak or no fluorescent signal are considered to be strong internalizers for that individual test anti-CD115 mAb. This procedure was repeated with several purified AlivaMab® Mouse anti-CD115 mAbs that showed internalization as a supernatant at 20 ug/ml. Other AlivaMab® Mouse anti-CD115 mAbs are also shown to exhibit various levels of internalization of CD115 induced by mAb binding (FIG. 12 and Table 10).

TABLE 10 Internalization of Anti-CD115 mAbs mAb Internalization CCK-423A − CCK-543A + CCK-416A ++ CCL-252A +++ CCL-331A ++++ (− = no internalization, 1-4 + = strength of internalization)

Example 6 Neutralization of CSF-1 Binding to CD115

Anti-CD115 antibodies were tested for their ability to block binding of recombinant CSF-1 to recombinant CD115. ELISA plates were coated with recombinant hu-CD115 (Sino Biological, China #10161-H08H) at 0.5 ug/ml and blocked with Superblock (Thermo Scientific #37518). Wells were incubated for 15 min with anti-CD115 mAbs, then biotinylated Hu-CSF-1 (R&D Systems, #216-MC-005) (biotinylation using NHS-Peg4-biotin, Life Technologies, #21330) was added to a final concentration of 0.25 ug/ml for an additional 15′. After a 4× wash, CSF-1-biotin was detected using 1:10,000 SAV-poly HRP (Life Technologies, #N200). Other AlivaMab® Mouse anti-CD115 mAbs are also shown to exhibit various abilities and IC50 values in blocking CSF-1 binding to CD115 (FIG. 10 and Table 11).

TABLE 11 AlivaMab Mouse anti-CD115 mAbs block CSF-1 binding to CD115 mAb IC₅₀ (pM) CCK-415A 355 CCK-416A 811 CCK-423A 135

Example 7 Inhibition of P-Tyr Formation on CD115 Induced by CSF-1

Anti-CD115 antibodies were tested for their ability to block hu-CSF1 induced phosphorylation of native CD115. OCI-AML5 cells (DSMZ, #ACC-247) were serum starved (1% FBS) overnight, then harvested and washed twice in PBS with 0.1% BSA. 250,000 cells were plated per well into a 96-well v-bottom polypropylene plate. Anti-CD115 supernatants were added neat for 15 min while incubating the plate on ice. Hu-CSF-1 (R&D Systems, #216-MC-005) was added to each well at a final concentration of 100 ng/ml and incubated for 30′ on ice. Cells were then spun down at 1500 RPM for 5′ at 4° C. and supernatant was removed. Cells were then resuspended in lysis buffer (Cell Signaling, #9803 with 1×HALT protease inhibitors, Pierce, #78430) and incubated on ice for 15 min. Lysates were then measured for tyrosine phosphorylated CD115 using a p-MCSFR validated DUOSET assay (R&D Systems #CYC3268E) and detected using Supersignal Pico ELISA Substrate (Pierce, #37069) (FIGS. 6 and 8 ).

Unpurified anti-CD115 IgGs (as identified by ELISA as described above) secreted from hybridomas into the tissue culture supernatant was assessed for neutralization of P-TYR formation induced by CSF-1. Neutralization using these unpurified, non-quantified antibodies was rank ordered. From this assessment, sets of the better neutralizing mAbs were identified, one set of IgGκ mAbs and one set of IgGλ mAbs. The hybridomas making these mAbs were grown and mAb purified using a commercially-available kit.

The P-TYR neutralization assay was repeated with several purified anti-CD115 mAbs using a dilution series enabling an IC50 calculation, first in an eight-point dilution curve (FIG. 9 ) and then with a further subset of best neutralizing mAbs in a twelve-point dilution curve to better calculate IC50 values. Of the antibodies tested, CCK423 was identified as having the best IC50 for neutralizing CSF-1 P-TYR formation on CD115 (FIGS. 11 and 16 ; Table 12).

TABLE 12 Anti-CD115 mAbs inhibit CSF-1 induced phosphorylation of CD115 mAb IC₅₀ (pM) CCK-415A 570 CCK-416A 1350 CCK-423A 45

Example 8 Conversion of Alivamab® Mouse Anti-CD115 mAbs to Fully Human

The AlivaMab® Mouse anti-CD115 mAbs are easily converted, expressed recombinantly and purified as fully-human antibodies of any isotype. The recombinant fully-human antibody retains all of the characteristics of the parental AlivaMab® Mouse antibody. For example, the nucleotide sequences of the heavy and light chain variable region of CCK423A were transmitted to and synthesized into DNA by Lake Pharma (Belmont Calif.) and then, using vectors for recombinant expression in mammalian cells, the VH cloned in-frame with coding sequences for human IgG1, IgG2, or IgG4 constant regions and the Vκ cloned in-frame with coding sequences for the human Cκ region. Vectors were then transformed into HEK293 cells for expression of recombinant fully human antibody. Fully human IgG1κ, IgG2κ and IgG4κ mAb versions of CCK423A were purified from tissue culture supernatants using protein A (FIG. 13 ).

Example 9 Affinity of Fully Human mAbs

Affinity was determined for AlivaMab® CCK423A as well as for the 3 human variants CCK423A-I IgG1κ, CCK423A-IgG2κ, and CCK423A-IgG4κ (Biosensor Tools, Salt Lake City, Utah). Binding kinetics were measured using a BioRad ProteOn XPR36 optical biosensor equipped with a GLM sensor chip. Purified mAbs were amine coupled to the GLM sensor chip. Hu CD115 (Sino Biological, China #10161-H08H) was tested in triplicate using a 3 fold dilution series starting at 10 nM. The processed data were fit using a 1:1 interaction model that includes a mass-transport parameter (Scrubber2, Canberra Australia). All 4 constructs were found to bind hu-CD115 with the same kinetics and affinity (Table 13).

TABLE 13 mAb ka (M⁻¹s⁻¹) kd (s⁻¹) KD (nM) AlivaMab CCK423A 1.3 × 10⁷ 1.5 × 10⁻² 1.2 Human IgG1κ 1.2 × 10⁷ 1.7 × 10⁻² 1.2 Human IgG2κ 1.3 × 10⁷ 1.4 × 10⁻² 1.3 Human IgG4κ 1.1 × 10⁷ 1.5 × 10⁻² 1.3

Example 10 CSF-1 Binding Neutralization with Fully Human mAbs

AlivaMab® Mouse CCK423A as well as the 3 human variants CCK423A-IgG1, CCK423A-IgG2, and CCK423A-IgG4 antibodies were tested for their ability to block binding of recombinant CSF-1 to recombinant CD115. ELISA plates were coated with recombinant hu-CD115 (Sino Biological, China #10161-H08H) at 0.5 ug/ml and blocked with Superblock (Thermo Scientific #37518). Wells were incubated for 15 min with anti-CD115 mAbs, then biotinylated Hu-CSF-1 (R&D Systems, #216-MC-005) (biotinylation using NHS-Peg4-biotin, Life Technologies, #21330) was added to a final concentration of 0.25 ug/ml for an additional 15′. After a 4× wash, CSF-1-biotin was detected using 1:10,000 SAV-poly HRP (Life Technologies, #N200). The fully human variants exhibited identical potency as the parental AlivaMab® antibody (FIG. 14 and Table 14).

TABLE 14 mAb IC₅₀ (pM) AlivaMab CCK423A 191 Human IgG1κ 146 Human IgG2κ 253 Human IgG4κ 133

Example 11 Inhibition of CSF-1 Induced P-Tyr with Fully Human Mabs

AlivaMab® Mouse CCK423A as well as the 3 human variants CCK423A-IgG1, CCK423A-IgG2, and CCK423A-IgG4 were tested for their ability to block hu-CSF1 induced phosphorylation of native CD115. OCI-AML5 cells (DSMZ, #ACC-247) were serum starved (1% FBS) overnight, then harvested and washed twice in PBS with 0.1% BSA. 250,000 cells were plated per well into a 96-well v-bottom polypropylene plate. Anti-CD115 mAbs were added in a dilution series for 15 min while incubating the plate on ice. Hu-CSF-1 (R&D Systems, #216-MC-005) was added to each well at a final concentration of 100 ng/ml and incubated for 30 min on ice. Cells were then spun down at 1500 RPM for 5 min at 4° C. and supernatant was removed. Cells were then resuspended in lysis buffer (Cell Signaling, #9803 with 1×HALT protease inhibitors, Pierce, #78430) and incubated on ice for 15 min. Lysates were then measured for tyrosine phosphorylated-CD115 using a p-MCSFR validated duoset assay (R&D Systems #CYC3268E) and detected using Supersignal Pico ELISA Substrate (Pierce, #37069). The fully human variants exhibited identical potency as the parental AlivaMab® antibody (FIG. 15 and Table 15).

TABLE 15 mAb IC₅₀ (pM) AlivaMab CCK423A 58 Human IgG1κ 68 Human IgG2κ 59 Human IgG4κ 60

Example 12 Inhibition of P-Tyr Formation on CD115 Induced by IL-34

Anti-CD115 antibodies of the invention were found to neutralize P-TYR formation on CD115 induced by interleukin-34 (IL-34). Some antibodies that block CSF-1 induced P-TYR formation on CD115 are found to also block IL-34 induced P-TYR formation on CD115. Other antibodies are found that block only CSF-1 induced P-TYR formation on CD115 and do not block IL-34 induced P-TYR formation on CD115. Antibodies are tested for their ability to block IL-34 induced phosphorylation of native CD115.

In an example assay, SR cells or other CD115+ IL-34 responsive cell line(s) are serum starved (1% FBS) overnight, then harvested and washed twice in PBS with 0.1% BSA. Cells are plated into a 96-well v-bottom polypropylene plate. Anti-CD115 antibodies, either in hybridoma supernatants, purified antibody, or in purified fully-human recombinant antibody format, are added for 15 min while incubating the plate on ice. Human IL-34 is added to each well at a final concentration sufficient and necessary to trigger P-TYR formation on CD115 and incubated for 30′ on ice. Cells were then spun down at 1500 RPM for 5′ at 4° C. and supernatant was removed. Cells were then resuspended in lysis buffer (Cell Signaling, #9803 with 1×HALT protease inhibitors, Pierce, #78430) and incubated on ice for 15 min. Lysates were then measured for tyrosine phosphorylated CD115 using a p-MCSFR validated DUOSET assay (R&D Systems #CYC3268E) and detected using Supersignal Pico ELISA Substrate (Pierce, #37069).

Example 13 Neutralization of IL-34 Binding to CD115

AlivaMab® Mouse anti-CD115 antibodies block binding of IL-34 to CD115. For example, anti-CD115 antibodies were tested for their ability to block binding of recombinant human IL-34 to recombinant CD115. ELISA plates were coated with recombinant hu-CD115 (Sino Biological, China #10161-H08H) at 0.5 ug/ml and blocked with Superblock (Thermo Scientific #37518). Wells were incubated for 15 min with anti-CD115 mAbs, then biotinylated Hu-IL-34 (biotinylation using NHS-Peg4-biotin, Life Technologies, #21330) is added for an additional 15 minutes. After a 4× wash, HU-IL-34-biotin was detected using 1:10,000 SAV-poly HRP (Life Technologies, #N200). Other AlivaMab® Mouse anti-CD115 mAbs are also shown to exhibit various abilities and IC50 values in blocking HU-IL-34 binding to CD115.

Example 14 Neutralization of P-Tyr Formation on CD115 without Neutralization of Binding of CSF-1 and IL-34

AlivaMab® Mouse anti-CD115 mAbs were found that neutralize p-Tyr formation in cells exposed to either CSF-1 or IL-34. However, these mAbs still allow binding of CSF-1 and IL-34 to CD115. This set of mAbs block p-Tyr formation through inhibition of dimerization of CD115.

Example 15 AlivaMab® Mouse Anti-CD115 Mabs and their Fully Human Derivatives Bind to and Neutralize CD115 from Cynomolgus Monkey

CD115 is cloned and expressed from cynomolgus monkey using standard molecular biological techniques. The recombinant CD115 may be tagged (histidine, Fc) to support efficient purification. The recombinant cynomolgus CD115 may also be transiently or stably expressed on cell lines. The AlivaMab® Mouse anti-CD115 mAbs and their human variants are shown to bind to cynomolgus monkey CD115. The AlivaMab® Mouse anti-CD115 mAbs and their human variants are shown to neutralize cynomolgus monkey CD115 in assays as described above for human CD115.

The various embodiments described above can be combined to provide further embodiments. All of the U.S. patents, U.S. patent application publications, U.S. patent application, foreign patents, foreign patent application and non-patent publications referred to in this specification and/or listed in the Application Data Sheet are incorporated herein by reference, in their entirety. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, application and publications to provide yet further embodiments.

These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure. 

What is claimed is:
 1. An isolated anti-CD115 antibody, or an antigen-binding fragment thereof, comprising: (a)(i) a heavy chain variable region (VH) comprising a heavy chain variable complementarity determining region 1 (HCDR1) comprising SEQ ID NO: 445; a HCDR2 comprising SEQ ID NO: 877; and a HCDR3 comprising SEQ ID NO: 1309; and (ii) a light chain variable region (VL) comprising a light chain variable complementarity determining region 1 (LCDR1) comprising SEQ ID NO: 661; a LCDR2 comprising SEQ ID NO: 1093; and a LCDR3 comprising SEQ ID NO: 1525, (b)(i) a heavy chain variable region comprising a VHCDR1 comprising SEQ ID NO: 481, a VHCDR2 comprising SEQ ID NO: 913, and a VHCDR3 comprising SEQ ID NO: 1345 and (ii) a light chain variable region comprising a VLCDR1 comprising SEQ ID NO: 697, a VLCDR2 comprising SEQ ID NO: 1129, and a VLCDR3 comprising SEQ ID NO: 1561, or (c)(i) a heavy chain variable region comprising a VHCDR1 comprising SEQ ID NO: 533, a VHCDR2 comprising SEQ ID NO: 965, and a VHCDR3 comprising SEQ ID NO: 1397 and (ii) a light chain variable region comprising a VLCDR1 comprising SEQ ID NO: 749, a VLCDR2 comprising SEQ ID NO: 1181, and a VLCDR3 comprising SEQ ID NO:
 1613. 2. The antibody, or antigen-binding fragment thereof, of claim 1, wherein the HCDR1, HCDR2, and HCDR3 comprise SEQ ID NOs:445, 877 and 1309, respectively; and the LCDR1, LCDR2, and LCDR3 comprise SEQ ID NOs:661, 1093 and 1525, respectively.
 3. The antibody, or antigen-binding fragment thereof, of claim 1, wherein the HCDR1, HCDR2, and HCDR3 comprise SEQ ID NOs:481, 913 and 1345, respectively; and the LCDR1, LCDR2, and LCDR3 comprise SEQ ID NOs:697, 1129 and 1561, respectively.
 4. The antibody, or antigen-binding fragment thereof, of claim 1, wherein the HCDR1, HCDR2, and HCDR3 comprise SEQ ID NOs: 533, 965 and 1397, respectively; and the LCDR1, LCDR2, and LCDR3 comprise SEQ ID NOs:749, 1181 and 1613, respectively.
 5. The antibody, or antigen-binding fragment thereof, of claim 1, wherein the VH comprises a) SEQ ID NO: 118; b) SEQ ID NO:154; or c) SEQ ID NO:
 206. 6. The antibody, or antigen-binding fragment thereof, of claim 1, wherein the VL comprises a) SEQ ID NO:334; b) SEQ ID NO:370; or c) SEQ ID NO:
 422. 7. The antibody, or antigen-binding fragment thereof, of claim 2, wherein the VH comprises SEQ ID NO:118 and the VL comprises SEQ ID NO:
 334. 8. The antibody, or antigen-binding fragment thereof, of claim 3, wherein the VH comprises SEQ ID NO:154 and the VL comprises SEQ ID NO:
 370. 9. The antibody, or antigen-binding fragment thereof, of claim 4, wherein the VH comprises SEQ ID NO: 206 and the VL comprises SEQ ID NO:
 422. 10. The antibody, or antigen-binding fragment thereof, of claim 1, wherein the antibody is human.
 11. The antibody, or antigen-binding fragment thereof, of claim 1, wherein the antibody is chimeric.
 12. The antibody, or antigen-binding fragment thereof, of claim 1, wherein the antibody or fragment is selected from a single-variable domain antibody, a single chain antibody, a scFv, a bispecific antibody, a multi-specific antibody, a Fab, a F(ab′)2, and a whole antibody.
 13. A pharmaceutical composition comprising the antibody, or antigen-binding fragment thereof, of claim 1 and a physiologically acceptable carrier. 